51317237664 has 768 divisors, whose sum is σ = 192819916800. Its totient is φ = 13056215040.

The previous prime is 51317237641. The next prime is 51317237717. The reversal of 51317237664 is 46673271315.

51317237664 is a `hidden beast` number, since 51 + 3 + 172 + 376 + 64 = 666.

Its product of digits (635040) is a multiple of the sum of its prime factors (245).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 479600299 + ... + 479600405.

It is an arithmetic number, because the mean of its divisors is an integer number (251067600).

Almost surely, 2^51317237664 is an apocalyptic number.

51317237664 is a gapful number since it is divisible by the number (54) 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 51317237664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96409958400).

51317237664 is an abundant number, since it is smaller than the sum of its proper divisors (141502679136).

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

51317237664 is a wasteful number, since it uses less digits than its factorization.

51317237664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245 (or 219 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The spelling of 51317237664 in words is "fifty-one billion, three hundred seventeen million, two hundred thirty-seven thousand, six hundred sixty-four".