21252558916 has 6 divisors (see below), whose sum is σ = 37191978110. Its totient is φ = 10626279456.

The previous prime is 21252558913. The next prime is 21252558949. The reversal of 21252558916 is 61985525212.

It can be written as a sum of positive squares in only one way, i.e., 13281640516 + 7970918400 = 115246^2 + 89280^2 .

It is not an unprimeable number, because it can be changed into a prime (21252558913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2656569861 + ... + 2656569868.

Almost surely, 2^21252558916 is an apocalyptic number.

It is an amenable number.

21252558916 is a deficient number, since it is larger than the sum of its proper divisors (15939419194).

21252558916 is a wasteful number, since it uses less digits than its factorization.

21252558916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5313139733 (or 5313139731 counting only the distinct ones).

The product of its digits is 432000, while the sum is 46.

It can be divided in two parts, 212525 and 58916, that added together give a square (271441 = 521²).

The spelling of 21252558916 in words is "twenty-one billion, two hundred fifty-two million, five hundred fifty-eight thousand, nine hundred sixteen".