21312112032 has 72 divisors (see below), whose sum is σ = 61459987680. Its totient is φ = 7003973760.

The previous prime is 21312112009. The next prime is 21312112039. The reversal of 21312112032 is 23021121312.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21312112032² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21312111996 and 21312112014.

It is not an unprimeable number, because it can be changed into a prime (21312112039) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 500682 + ... + 541577.

It is an arithmetic number, because the mean of its divisors is an integer number (853610940).

Almost surely, 2^21312112032 is an apocalyptic number.

It is an amenable number.

21312112032 is an abundant number, since it is smaller than the sum of its proper divisors (40147875648).

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

21312112032 is a wasteful number, since it uses less digits than its factorization.

21312112032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042346 (or 1042335 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21312112032 its reverse (23021121312), we get a palindrome (44333233344).

The spelling of 21312112032 in words is "twenty-one billion, three hundred twelve million, one hundred twelve thousand, thirty-two".