1201111111 has 4 divisors (see below), whose sum is σ = 1201275400. Its totient is φ = 1200946824.

The previous prime is 1201111091. The next prime is 1201111117. The reversal of 1201111111 is 1111111021.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1201111111 - 2¹³ = 1201102919 is a prime.

It is a super-3 number, since 3×1201111111³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

1201111111 is a modest number, since divided by 111111 gives 1201 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201111117) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70641 + ... + 85978.

It is an arithmetic number, because the mean of its divisors is an integer number (300318850).

Almost surely, 2^1201111111 is an apocalyptic number.

1201111111 is a deficient number, since it is larger than the sum of its proper divisors (164289).

1201111111 is an equidigital number, since it uses as much as digits as its factorization.

1201111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164288.

The product of its (nonzero) digits is 2, while the sum is 10.

The square root of 1201111111 is about 34657.0499465837. The cubic root of 1201111111 is about 1062.9864490130.

Adding to 1201111111 its reverse (1111111021), we get a palindrome (2312222132).

The spelling of 1201111111 in words is "one billion, two hundred one million, one hundred eleven thousand, one hundred eleven".