21525504520 has 64 divisors (see below), whose sum is σ = 52892663040. Its totient is φ = 7835923200.

The previous prime is 21525504509. The next prime is 21525504521. The reversal of 21525504520 is 2540552512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21525504521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254596 + ... + 328435.

It is an arithmetic number, because the mean of its divisors is an integer number (826447860).

Almost surely, 2^21525504520 is an apocalyptic number.

21525504520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21525504520 is an abundant number, since it is smaller than the sum of its proper divisors (31367158520).

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

21525504520 is a wasteful number, since it uses less digits than its factorization.

21525504520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583126 (or 583122 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 31.

The spelling of 21525504520 in words is "twenty-one billion, five hundred twenty-five million, five hundred four thousand, five hundred twenty".