21525213432 has 16 divisors (see below), whose sum is σ = 53813033640. Its totient is φ = 7175071136.

The previous prime is 21525213421. The next prime is 21525213467. The reversal of 21525213432 is 23431252512.

It is a self number, because there is not a number n which added to its sum of digits gives 21525213432.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 448441923 + ... + 448441970.

Almost surely, 2^21525213432 is an apocalyptic number.

It is an amenable number.

21525213432 is an abundant number, since it is smaller than the sum of its proper divisors (32287820208).

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

21525213432 is a wasteful number, since it uses less digits than its factorization.

21525213432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 896883902 (or 896883898 counting only the distinct ones).

The product of its digits is 14400, while the sum is 30.

Adding to 21525213432 its reverse (23431252512), we get a palindrome (44956465944).

The spelling of 21525213432 in words is "twenty-one billion, five hundred twenty-five million, two hundred thirteen thousand, four hundred thirty-two".