51643578765 has 16 divisors (see below), whose sum is σ = 83000268288. Its totient is φ = 27419727936.

The previous prime is 51643578743. The next prime is 51643578787. The reversal of 51643578765 is 56787534615.

It is an interprime number because it is at equal distance from previous prime (51643578743) and next prime (51643578787).

It is not a de Polignac number, because 51643578765 - 2⁵ = 51643578733 is a prime.

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, 7716174 + ... + 7722863.

It is an arithmetic number, because the mean of its divisors is an integer number (5187516768).

Almost surely, 2^51643578765 is an apocalyptic number.

It is an amenable number.

51643578765 is a deficient number, since it is larger than the sum of its proper divisors (31356689523).

51643578765 is a wasteful number, since it uses less digits than its factorization.

51643578765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15439268.

The product of its digits is 21168000, while the sum is 57.

The spelling of 51643578765 in words is "fifty-one billion, six hundred forty-three million, five hundred seventy-eight thousand, seven hundred sixty-five".