51631765920 has 288 divisors, whose sum is σ = 201610176768. Its totient is φ = 11787116544.

The previous prime is 51631765919. The next prime is 51631765957. The reversal of 51631765920 is 2956713615.

51631765920 is a `hidden beast` number, since 5 + 1 + 631 + 7 + 6 + 5 + 9 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 9744712 + ... + 9750008.

It is an arithmetic number, because the mean of its divisors is an integer number (700035336).

Almost surely, 2^51631765920 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 51631765920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100805088384).

51631765920 is an abundant number, since it is smaller than the sum of its proper divisors (149978410848).

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

51631765920 is a wasteful number, since it uses less digits than its factorization.

51631765920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6292 (or 6281 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The spelling of 51631765920 in words is "fifty-one billion, six hundred thirty-one million, seven hundred sixty-five thousand, nine hundred twenty".