51636653643 has 4 divisors (see below), whose sum is σ = 68848871528. Its totient is φ = 34424435760.

The previous prime is 51636653623. The next prime is 51636653669. The reversal of 51636653643 is 34635663615.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 51636653643 - 2⁵ = 51636653611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51636653592 and 51636653601.

It is not an unprimeable number, because it can be changed into a prime (51636653623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8606108938 + ... + 8606108943.

It is an arithmetic number, because the mean of its divisors is an integer number (17212217882).

Almost surely, 2^51636653643 is an apocalyptic number.

51636653643 is a deficient number, since it is larger than the sum of its proper divisors (17212217885).

51636653643 is a wasteful number, since it uses less digits than its factorization.

51636653643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17212217884.

The product of its digits is 3499200, while the sum is 48.

The spelling of 51636653643 in words is "fifty-one billion, six hundred thirty-six million, six hundred fifty-three thousand, six hundred forty-three".