21699963855684 has 81 divisors (see below), whose sum is σ = 55408367566461. Its totient is φ = 7160772578400.

The previous prime is 21699963855679. The next prime is 21699963855727. The reversal of 21699963855684 is 48655836999612.

The square root of 21699963855684 is 4658322.

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

21699963855684 is a `hidden beast` number, since 2 + 1 + 6 + 99 + 96 + 385 + 5 + 68 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20849068302084 + 850895553600 = 4566078^2 + 922440^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 2822939289 + ... + 2822946975.

Almost surely, 2^{21699963855684} is an apocalyptic number.

21699963855684 is the 4658322-nd square number.

It is an amenable number.

21699963855684 is an abundant number, since it is smaller than the sum of its proper divisors (33708403710777).

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

21699963855684 is an frugal number, since it uses more digits than its factorization.

21699963855684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15586 (or 7793 counting only the distinct ones).

The product of its digits is 6046617600, while the sum is 81.

The spelling of 21699963855684 in words is "twenty-one trillion, six hundred ninety-nine billion, nine hundred sixty-three million, eight hundred fifty-five thousand, six hundred eighty-four".