51863215777920 has 384 divisors, whose sum is σ = 190382500526400. Its totient is φ = 12972557721600.

The previous prime is 51863215777913. The next prime is 51863215777973. The reversal of 51863215777920 is 2977751236815.

It is a happy number.

51863215777920 is a `hidden beast` number, since 5 + 1 + 8 + 6 + 32 + 1 + 577 + 7 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8707419 + ... + 13399461.

Almost surely, 2^{51863215777920} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51863215777920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95191250263200).

51863215777920 is an abundant number, since it is smaller than the sum of its proper divisors (138519284748480).

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

51863215777920 is a wasteful number, since it uses less digits than its factorization.

51863215777920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4692188 (or 4692173 counting only the distinct ones).

The product of its (nonzero) digits is 44452800, while the sum is 63.

The spelling of 51863215777920 in words is "fifty-one trillion, eight hundred sixty-three billion, two hundred fifteen million, seven hundred seventy-seven thousand, nine hundred twenty".