20871956066400 has 432 divisors, whose sum is σ = 74071391940000. Its totient is φ = 5530241433600.

The previous prime is 20871956066371. The next prime is 20871956066447. The reversal of 20871956066400 is 466065917802.

20871956066400 is a `hidden beast` number, since 2 + 0 + 8 + 7 + 19 + 560 + 6 + 64 + 0 + 0 = 666.

It is a super-2 number, since 2×20871956066400² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1627690389 + ... + 1627703211.

Almost surely, 2^{20871956066400} is an apocalyptic number.

20871956066400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20871956066400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37035695970000).

20871956066400 is an abundant number, since it is smaller than the sum of its proper divisors (53199435873600).

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

20871956066400 is a wasteful number, since it uses less digits than its factorization.

20871956066400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14279 (or 14263 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 20871956066400 in words is "twenty trillion, eight hundred seventy-one billion, nine hundred fifty-six million, sixty-six thousand, four hundred".