21407232825 has 120 divisors (see below), whose sum is σ = 43395168960. Its totient is φ = 10346486400.

The previous prime is 21407232817. The next prime is 21407232829. The reversal of 21407232825 is 52823270412.

It is not a de Polignac number, because 21407232825 - 2³ = 21407232817 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21407232825.

It is not an unprimeable number, because it can be changed into a prime (21407232829) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 7995387 + ... + 7998063.

It is an arithmetic number, because the mean of its divisors is an integer number (361626408).

Almost surely, 2^21407232825 is an apocalyptic number.

21407232825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21407232825 is an abundant number, since it is smaller than the sum of its proper divisors (21987936135).

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

21407232825 is a wasteful number, since it uses less digits than its factorization.

21407232825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3069 (or 3055 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The spelling of 21407232825 in words is "twenty-one billion, four hundred seven million, two hundred thirty-two thousand, eight hundred twenty-five".