642615346521 has 6 divisors (see below), whose sum is σ = 928222167210. Its totient is φ = 428410231008.

The previous prime is 642615346511. The next prime is 642615346589. The reversal of 642615346521 is 125643516246.

642615346521 is a `hidden beast` number, since 6 + 4 + 2 + 61 + 534 + 6 + 52 + 1 = 666.

642615346521 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 only one way, i.e., 501213025296 + 141402321225 = 707964^2 + 376035^2 .

It is not a de Polignac number, because 642615346521 - 2⁵ = 642615346489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642615346501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35700852576 + ... + 35700852593.

It is an arithmetic number, because the mean of its divisors is an integer number (154703694535).

Almost surely, 2^642615346521 is an apocalyptic number.

It is an amenable number.

642615346521 is a deficient number, since it is larger than the sum of its proper divisors (285606820689).

642615346521 is a wasteful number, since it uses less digits than its factorization.

642615346521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71401705175 (or 71401705172 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The spelling of 642615346521 in words is "six hundred forty-two billion, six hundred fifteen million, three hundred forty-six thousand, five hundred twenty-one".