21375024804 has 135 divisors (see below), whose sum is σ = 63936419547. Its totient is φ = 6003638928.

The previous prime is 21375024791. The next prime is 21375024821. The reversal of 21375024804 is 40842057312.

It is a happy number.

The square root of 21375024804 is 146202.

It is a perfect power (a square), and thus also a powerful number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 362288527 + ... + 362288585.

Almost surely, 2^21375024804 is an apocalyptic number.

21375024804 is the 146202-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21375024804

21375024804 is an abundant number, since it is smaller than the sum of its proper divisors (42561394743).

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

21375024804 is an frugal number, since it uses more digits than its factorization.

21375024804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260 (or 71 counting only the distinct ones).

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

Multiplying 21375024804 by its sum of digits (36), we get a square (769500892944 = 877212²).

21375024804 divided by its sum of digits (36) gives a square (593750689 = 24367²).

The spelling of 21375024804 in words is "twenty-one billion, three hundred seventy-five million, twenty-four thousand, eight hundred four".