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1111111111 = 11412719091

1111111111 has 16 divisors (see below), whose sum is σ = 1246404096. Its totient is φ = 981720000.

The previous prime is 1111111097. The next prime is 1111111121.

It can be divided in two parts, 11111111 and 11, that multiplied together give a palindrome (122222221).

It is a happy number.

1111111111 is nontrivially palindromic in base 10.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-1111111111 is a prime.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

1111111111 is a strobogrammatic number because it is the same when read upside-down.

It is a deceptive number, since it divides R1111111110.

It is a Duffinian number.

1111111111 is a modest number, since divided by 111111 gives 1111 as remainder.

1111111111 is a nontrivial repdigit in base 10.

It is a plaindrome in base 10.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111111121) by changing a digit.

It is a nontrivial repunit in base 10.

It is a Kaprekar number, because its square (1234567900987654321) can be partitioned into two parts whose sum is 1111111111.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117676 + ... + 126766.

It is an arithmetic number, because the mean of its divisors is an integer number (77900256).

Almost surely, 21111111111 is an apocalyptic number.

1111111111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1111111111 is a deficient number, since it is larger than the sum of its proper divisors (135292985).

1111111111 is a wasteful number, since it uses less digits than its factorization.

1111111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9414.

The product of its digits is 1, while the sum is 10.

The square root of 1111111111 is about 33333.3333316667. Note that the first 5 decimals coincide. The cubic root of 1111111111 is about 1035.7441686168.

The spelling of 1111111111 in words is "one billion, one hundred eleven million, one hundred eleven thousand, one hundred eleven".

Divisors: 1 11 41 271 451 2981 9091 11111 100001 122221 372731 2463661 4100041 27100271 101010101 1111111111