21525245404 has 18 divisors (see below), whose sum is σ = 40789704480. Its totient is φ = 9934728336.

The previous prime is 21525245387. The next prime is 21525245473. The reversal of 21525245404 is 40454252512.

It is a self number, because there is not a number n which added to its sum of digits gives 21525245404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15920364 + ... + 15921715.

Almost surely, 2^21525245404 is an apocalyptic number.

It is an amenable number.

21525245404 is a deficient number, since it is larger than the sum of its proper divisors (19264459076).

21525245404 is a wasteful number, since it uses less digits than its factorization.

21525245404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31842109 (or 31842094 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 34.

Adding to 21525245404 its reverse (40454252512), we get a palindrome (61979497916).

The spelling of 21525245404 in words is "twenty-one billion, five hundred twenty-five million, two hundred forty-five thousand, four hundred four".