51005591965 has 16 divisors (see below), whose sum is σ = 61864997040. Its totient is φ = 40365987840.

The previous prime is 51005591921. The next prime is 51005591983. The reversal of 51005591965 is 56919550015.

51005591965 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 4061003076 + 46944588889 = 63726^2 + 216667^2 .

It is a de Polignac number, because none of the positive numbers 2^k-51005591965 is a prime.

It is a super-2 number, since 2×51005591965² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1136655 + ... + 1180675.

It is an arithmetic number, because the mean of its divisors is an integer number (3866562315).

Almost surely, 2^51005591965 is an apocalyptic number.

It is an amenable number.

51005591965 is a deficient number, since it is larger than the sum of its proper divisors (10859405075).

51005591965 is a wasteful number, since it uses less digits than its factorization.

51005591965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46512.

The product of its (nonzero) digits is 303750, while the sum is 46.

The spelling of 51005591965 in words is "fifty-one billion, five million, five hundred ninety-one thousand, nine hundred sixty-five".