21573146884 has 81 divisors (see below), whose sum is σ = 41179732839. Its totient is φ = 9887826960.

The previous prime is 21573146843. The next prime is 21573146921. The reversal of 21573146884 is 48864137512.

The square root of 21573146884 is 146878.

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

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 209447977 + ... + 209448079.

Almost surely, 2^21573146884 is an apocalyptic number.

21573146884 is the 146878-th square number.

It is an amenable number.

21573146884 is a deficient number, since it is larger than the sum of its proper divisors (19606585955).

21573146884 is a wasteful number, since it uses less digits than its factorization.

21573146884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318 (or 159 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 49.

Multiplying 21573146884 by its sum of digits (49), we get a square (1057084197316 = 1028146²).

The spelling of 21573146884 in words is "twenty-one billion, five hundred seventy-three million, one hundred forty-six thousand, eight hundred eighty-four".