51391791360 has 1080 divisors, whose sum is σ = 228111871680. Its totient is φ = 10817224704.

The previous prime is 51391791331. The next prime is 51391791389. The reversal of 51391791360 is 6319719315.

It is a happy number.

51391791360 is a `hidden beast` number, since 513 + 9 + 1 + 79 + 1 + 3 + 60 = 666.

It is an interprime number because it is at equal distance from previous prime (51391791331) and next prime (51391791389).

It is a tau number, because it is divible by the number of its divisors (1080).

It is a super-2 number, since 2×51391791360² (a number of 22 digits) contains 22 as substring.

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 119 ways as a sum of consecutive naturals, for example, 122653231 + ... + 122653649.

It is an arithmetic number, because the mean of its divisors is an integer number (211214696).

Almost surely, 2^51391791360 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 51391791360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114055935840).

51391791360 is an abundant number, since it is smaller than the sum of its proper divisors (176720080320).

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

51391791360 is a wasteful number, since it uses less digits than its factorization.

51391791360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 153090, while the sum is 45.

The spelling of 51391791360 in words is "fifty-one billion, three hundred ninety-one million, seven hundred ninety-one thousand, three hundred sixty".