51821838564 has 12 divisors (see below), whose sum is σ = 120917623344. Its totient is φ = 17273946184.

The previous prime is 51821838511. The next prime is 51821838577. The reversal of 51821838564 is 46583812815.

It is a tau number, because it is divible by the number of its divisors (12).

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, 2159243262 + ... + 2159243285.

It is an arithmetic number, because the mean of its divisors is an integer number (10076468612).

Almost surely, 2^51821838564 is an apocalyptic number.

It is an amenable number.

51821838564 is an abundant number, since it is smaller than the sum of its proper divisors (69095784780).

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

51821838564 is a wasteful number, since it uses less digits than its factorization.

51821838564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4318486554 (or 4318486552 counting only the distinct ones).

The product of its digits is 1843200, while the sum is 51.

The spelling of 51821838564 in words is "fifty-one billion, eight hundred twenty-one million, eight hundred thirty-eight thousand, five hundred sixty-four".