21453025520520 has 192 divisors, whose sum is σ = 78877791195840. Its totient is φ = 5200733433600.

The previous prime is 21453025520501. The next prime is 21453025520557. The reversal of 21453025520520 is 2502552035412.

21453025520520 is a `hidden beast` number, since 2 + 1 + 4 + 53 + 0 + 2 + 552 + 0 + 52 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 100215871 + ... + 100429710.

It is an arithmetic number, because the mean of its divisors is an integer number (410821829145).

Almost surely, 2^{21453025520520} is an apocalyptic number.

21453025520520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21453025520520 is an abundant number, since it is smaller than the sum of its proper divisors (57424765675320).

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

21453025520520 is a wasteful number, since it uses less digits than its factorization.

21453025520520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200645618 (or 200645602 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 36.

Adding to 21453025520520 its reverse (2502552035412), we get a palindrome (23955577555932).

The spelling of 21453025520520 in words is "twenty-one trillion, four hundred fifty-three billion, twenty-five million, five hundred twenty thousand, five hundred twenty".