51656693945472 has 768 divisors, whose sum is σ = 196474960281600. Its totient is φ = 12612199219200.

The previous prime is 51656693945459. The next prime is 51656693945509. The reversal of 51656693945472 is 27454939665615.

It is a happy number.

51656693945472 is a `hidden beast` number, since 5 + 1 + 6 + 5 + 6 + 69 + 3 + 94 + 5 + 472 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 51656693945472.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1222940929 + ... + 1222983167.

It is an arithmetic number, because the mean of its divisors is an integer number (255826771200).

Almost surely, 2^{51656693945472} 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 51656693945472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98237480140800).

51656693945472 is an abundant number, since it is smaller than the sum of its proper divisors (144818266336128).

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

51656693945472 is a wasteful number, since it uses less digits than its factorization.

51656693945472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43105 (or 43090 counting only the distinct ones).

The product of its digits is 1469664000, while the sum is 72.

The spelling of 51656693945472 in words is "fifty-one trillion, six hundred fifty-six billion, six hundred ninety-three million, nine hundred forty-five thousand, four hundred seventy-two".