21265731432 has 96 divisors (see below), whose sum is σ = 62885047680. Its totient is φ = 6438574080.

The previous prime is 21265731413. The next prime is 21265731433. The reversal of 21265731432 is 23413756212.

21265731432 is a `hidden beast` number, since 21 + 26 + 573 + 1 + 43 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21265731433) 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, 952833 + ... + 974895.

It is an arithmetic number, because the mean of its divisors is an integer number (655052580).

Almost surely, 2^21265731432 is an apocalyptic number.

21265731432 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21265731432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31442523840).

21265731432 is an abundant number, since it is smaller than the sum of its proper divisors (41619316248).

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

21265731432 is a wasteful number, since it uses less digits than its factorization.

21265731432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23303 (or 23296 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The spelling of 21265731432 in words is "twenty-one billion, two hundred sixty-five million, seven hundred thirty-one thousand, four hundred thirty-two".