642397764 has 12 divisors (see below), whose sum is σ = 1498928144. Its totient is φ = 214132584.

The previous prime is 642397759. The next prime is 642397793. The reversal of 642397764 is 467793246.

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, 26766562 + ... + 26766585.

Almost surely, 2^642397764 is an apocalyptic number.

It is an amenable number.

642397764 is an abundant number, since it is smaller than the sum of its proper divisors (856530380).

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

642397764 is a wasteful number, since it uses less digits than its factorization.

642397764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53533154 (or 53533152 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 48.

The square root of 642397764 is about 25345.5669496660. The cubic root of 642397764 is about 862.8487485269.

The spelling of 642397764 in words is "six hundred forty-two million, three hundred ninety-seven thousand, seven hundred sixty-four".