51643494624 has 24 divisors (see below), whose sum is σ = 135564173640. Its totient is φ = 17214498176.

The previous prime is 51643494619. The next prime is 51643494649. The reversal of 51643494624 is 42649434615.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268976439 + ... + 268976630.

It is an arithmetic number, because the mean of its divisors is an integer number (5648507235).

Almost surely, 2^51643494624 is an apocalyptic number.

It is an amenable number.

51643494624 is an abundant number, since it is smaller than the sum of its proper divisors (83920679016).

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

51643494624 is a wasteful number, since it uses less digits than its factorization.

51643494624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537953082 (or 537953074 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 48.

The spelling of 51643494624 in words is "fifty-one billion, six hundred forty-three million, four hundred ninety-four thousand, six hundred twenty-four".