21111112011 has 32 divisors (see below), whose sum is σ = 31767676416. Its totient is φ = 12358880000.

The previous prime is 21111111997. The next prime is 21111112013. The reversal of 21111112011 is 11021111112.

It is a cyclic number.

It is not a de Polignac number, because 21111112011 - 2⁶ = 21111111947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21111112013) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59410 + ... + 213896.

It is an arithmetic number, because the mean of its divisors is an integer number (992739888).

Almost surely, 2^21111112011 is an apocalyptic number.

21111112011 is a deficient number, since it is larger than the sum of its proper divisors (10656564405).

21111112011 is a wasteful number, since it uses less digits than its factorization.

21111112011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154643.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21111112011 its reverse (11021111112), we get a palindrome (32132223123).

The spelling of 21111112011 in words is "twenty-one billion, one hundred eleven million, one hundred twelve thousand, eleven".