20865993868404 has 36 divisors (see below), whose sum is σ = 52744734178500. Its totient is φ = 6955313016960.

The previous prime is 20865993868319. The next prime is 20865993868429. The reversal of 20865993868404 is 40486839956802.

It is a happy number.

20865993868404 is a `hidden beast` number, since 2 + 0 + 8 + 6 + 59 + 93 + 86 + 8 + 404 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2859108992100 + 18006884876304 = 1690890^2 + 4243452^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26768734 + ... + 27537194.

Almost surely, 2^{20865993868404} is an apocalyptic number.

It is an amenable number.

20865993868404 is an abundant number, since it is smaller than the sum of its proper divisors (31878740310096).

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

20865993868404 is a wasteful number, since it uses less digits than its factorization.

20865993868404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1522720 (or 1522715 counting only the distinct ones).

The product of its (nonzero) digits is 716636160, while the sum is 72.

The spelling of 20865993868404 in words is "twenty trillion, eight hundred sixty-five billion, nine hundred ninety-three million, eight hundred sixty-eight thousand, four hundred four".