1021111111 has 4 divisors (see below), whose sum is σ = 1031221224. Its totient is φ = 1011001000.

The previous prime is 1021111099. The next prime is 1021111121. The reversal of 1021111111 is 1111111201.

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 1021111111 - 2⁷ = 1021110983 is a prime.

It is a Duffinian number.

1021111111 is a modest number, since divided by 11111 gives 10211 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021111121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5054905 + ... + 5055106.

It is an arithmetic number, because the mean of its divisors is an integer number (257805306).

Almost surely, 2^1021111111 is an apocalyptic number.

1021111111 is a deficient number, since it is larger than the sum of its proper divisors (10110113).

1021111111 is a wasteful number, since it uses less digits than its factorization.

1021111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10110112.

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

The square root of 1021111111 is about 31954.8292281464. The cubic root of 1021111111 is about 1006.9880898495.

Adding to 1021111111 its reverse (1111111201), we get a palindrome (2132222312).

The spelling of 1021111111 in words is "one billion, twenty-one million, one hundred eleven thousand, one hundred eleven".