21312400232 has 8 divisors (see below), whose sum is σ = 39960750450. Its totient is φ = 10656200112.

The previous prime is 21312400189. The next prime is 21312400247. The reversal of 21312400232 is 23200421312.

It can be written as a sum of positive squares in only one way, i.e., 12059114596 + 9253285636 = 109814^2 + 96194^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1332025007 + ... + 1332025022.

Almost surely, 2^21312400232 is an apocalyptic number.

It is an amenable number.

21312400232 is a deficient number, since it is larger than the sum of its proper divisors (18648350218).

21312400232 is a wasteful number, since it uses less digits than its factorization.

21312400232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664050035 (or 2664050031 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21312400232 its reverse (23200421312), we get a palindrome (44512821544).

The spelling of 21312400232 in words is "twenty-one billion, three hundred twelve million, four hundred thousand, two hundred thirty-two".