21637968665058 has 80 divisors (see below), whose sum is σ = 49614558950880. Its totient is φ = 7044647246784.

The previous prime is 21637968665057. The next prime is 21637968665099. The reversal of 21637968665058 is 85056686973612.

21637968665058 is a `hidden beast` number, since 2 + 1 + 6 + 37 + 9 + 6 + 86 + 6 + 505 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (21637968665057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 261511038 + ... + 261593766.

It is an arithmetic number, because the mean of its divisors is an integer number (620181986886).

Almost surely, 2^{21637968665058} is an apocalyptic number.

21637968665058 is an abundant number, since it is smaller than the sum of its proper divisors (27976590285822).

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

21637968665058 is a wasteful number, since it uses less digits than its factorization.

21637968665058 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120333 (or 120324 counting only the distinct ones).

The product of its (nonzero) digits is 783820800, while the sum is 72.

The spelling of 21637968665058 in words is "twenty-one trillion, six hundred thirty-seven billion, nine hundred sixty-eight million, six hundred sixty-five thousand, fifty-eight".