21012090111 has 24 divisors (see below), whose sum is σ = 30625904400. Its totient is φ = 13881528576.

The previous prime is 21012090097. The next prime is 21012090163. The reversal of 21012090111 is 11109021012.

It is a happy number.

It is not a de Polignac number, because 21012090111 - 2¹⁴ = 21012073727 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012090311) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 562560 + ... + 598746.

It is an arithmetic number, because the mean of its divisors is an integer number (1276079350).

Almost surely, 2^21012090111 is an apocalyptic number.

21012090111 is a deficient number, since it is larger than the sum of its proper divisors (9613814289).

21012090111 is a wasteful number, since it uses less digits than its factorization.

21012090111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36775 (or 36772 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The spelling of 21012090111 in words is "twenty-one billion, twelve million, ninety thousand, one hundred eleven".