21131223232 has 56 divisors (see below), whose sum is σ = 48397180320. Its totient is φ = 8966553600.

The previous prime is 21131223209. The next prime is 21131223263. The reversal of 21131223232 is 23232213112.

It is a tau number, because it is divible by the number of its divisors (56).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188257 + ... + 278752.

Almost surely, 2^21131223232 is an apocalyptic number.

It is an amenable number.

21131223232 is an abundant number, since it is smaller than the sum of its proper divisors (27265957088).

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

21131223232 is a wasteful number, since it uses less digits than its factorization.

21131223232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467129 (or 467119 counting only the distinct ones).

The product of its digits is 864, while the sum is 22.

Adding to 21131223232 its reverse (23232213112), we get a palindrome (44363436344).

The spelling of 21131223232 in words is "twenty-one billion, one hundred thirty-one million, two hundred twenty-three thousand, two hundred thirty-two".