21508017258996 has 72 divisors (see below), whose sum is σ = 54766248091464. Its totient is φ = 7116759014400.

The previous prime is 21508017258947. The next prime is 21508017258997. The reversal of 21508017258996 is 69985271080512.

21508017258996 is a `hidden beast` number, since 2 + 1 + 508 + 0 + 1 + 72 + 58 + 9 + 9 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3467304684900 + 18040712574096 = 1862070^2 + 4247436^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21508017258997) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 187620096 + ... + 187734696.

Almost surely, 2^{21508017258996} is an apocalyptic number.

It is an amenable number.

21508017258996 is an abundant number, since it is smaller than the sum of its proper divisors (33258230832468).

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

21508017258996 is a wasteful number, since it uses less digits than its factorization.

21508017258996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152801 (or 152796 counting only the distinct ones).

The product of its (nonzero) digits is 21772800, while the sum is 63.

The spelling of 21508017258996 in words is "twenty-one trillion, five hundred eight billion, seventeen million, two hundred fifty-eight thousand, nine hundred ninety-six".