51135965820 has 60 divisors (see below), whose sum is σ = 160415423784. Its totient is φ = 13636257120.

The previous prime is 51135965819. The next prime is 51135965891. The reversal of 51135965820 is 2856953115.

51135965820 is a `hidden beast` number, since 5 + 1 + 1 + 3 + 596 + 58 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×51135965820² (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 a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15781086 + ... + 15784325.

Almost surely, 2^51135965820 is an apocalyptic number.

It is an amenable number.

51135965820 is an abundant number, since it is smaller than the sum of its proper divisors (109279457964).

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

51135965820 is a wasteful number, since it uses less digits than its factorization.

51135965820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31565432 (or 31565421 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 45.

The spelling of 51135965820 in words is "fifty-one billion, one hundred thirty-five million, nine hundred sixty-five thousand, eight hundred twenty".