51374891520 has 400 divisors, whose sum is σ = 185778477720. Its totient is φ = 13568311296.

The previous prime is 51374891509. The next prime is 51374891537. The reversal of 51374891520 is 2519847315.

51374891520 is a `hidden beast` number, since 5 + 1 + 37 + 4 + 8 + 91 + 520 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 50398454016 + 976437504 = 224496^2 + 31248^2 .

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 39 ways as a sum of consecutive naturals, for example, 22601104 + ... + 22603376.

Almost surely, 2^51374891520 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 51374891520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92889238860).

51374891520 is an abundant number, since it is smaller than the sum of its proper divisors (134403586200).

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

51374891520 is a wasteful number, since it uses less digits than its factorization.

51374891520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2417 (or 2392 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 51374891520 in words is "fifty-one billion, three hundred seventy-four million, eight hundred ninety-one thousand, five hundred twenty".