642724664 has 8 divisors (see below), whose sum is σ = 1205108760. Its totient is φ = 321362328.

The previous prime is 642724657. The next prime is 642724679. The reversal of 642724664 is 466427246.

642724664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40170284 + ... + 40170299.

It is an arithmetic number, because the mean of its divisors is an integer number (150638595).

Almost surely, 2^642724664 is an apocalyptic number.

It is an amenable number.

642724664 is a deficient number, since it is larger than the sum of its proper divisors (562384096).

642724664 is a wasteful number, since it uses less digits than its factorization.

642724664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80340589 (or 80340585 counting only the distinct ones).

The product of its digits is 387072, while the sum is 41.

The square root of 642724664 is about 25352.0149889511. The cubic root of 642724664 is about 862.9950843539.

The spelling of 642724664 in words is "six hundred forty-two million, seven hundred twenty-four thousand, six hundred sixty-four".