21023431212 has 48 divisors (see below), whose sum is σ = 56159774720. Its totient is φ = 5996270592.

The previous prime is 21023431207. The next prime is 21023431223. The reversal of 21023431212 is 21213432012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168412 + ... + 265347.

Almost surely, 2^21023431212 is an apocalyptic number.

It is an amenable number.

21023431212 is an abundant number, since it is smaller than the sum of its proper divisors (35136343508).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21023431212 is a wasteful number, since it uses less digits than its factorization.

21023431212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434350 (or 434348 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21023431212 its reverse (21213432012), we get a palindrome (42236863224).

The spelling of 21023431212 in words is "twenty-one billion, twenty-three million, four hundred thirty-one thousand, two hundred twelve".