642307664 has 10 divisors (see below), whose sum is σ = 1244471130. Its totient is φ = 321153824.

The previous prime is 642307607. The next prime is 642307697. The reversal of 642307664 is 466703246.

It can be written as a sum of positive squares in only one way, i.e., 635443264 + 6864400 = 25208^2 + 2620^2 .

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, 20072099 + ... + 20072130.

It is an arithmetic number, because the mean of its divisors is an integer number (124447113).

Almost surely, 2^642307664 is an apocalyptic number.

It is an amenable number.

642307664 is a deficient number, since it is larger than the sum of its proper divisors (602163466).

642307664 is a wasteful number, since it uses less digits than its factorization.

642307664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40144237 (or 40144231 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 38.

The square root of 642307664 is about 25343.7894561962. The cubic root of 642307664 is about 862.8084067991.

The spelling of 642307664 in words is "six hundred forty-two million, three hundred seven thousand, six hundred sixty-four".