642426964 has 12 divisors (see below), whose sum is σ = 1125912564. Its totient is φ = 320737664.

The previous prime is 642426959. The next prime is 642426979. The reversal of 642426964 is 469624246.

It can be written as a sum of positive squares in 2 ways, for example, as 640494864 + 1932100 = 25308^2 + 1390^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 642426964.

It is a congruent number.

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, 115909 + ... + 121324.

It is an arithmetic number, because the mean of its divisors is an integer number (93826047).

Almost surely, 2^642426964 is an apocalyptic number.

It is an amenable number.

642426964 is a deficient number, since it is larger than the sum of its proper divisors (483485600).

642426964 is a wasteful number, since it uses less digits than its factorization.

642426964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237914 (or 237912 counting only the distinct ones).

The product of its digits is 497664, while the sum is 43.

The square root of 642426964 is about 25346.1429807377. The cubic root of 642426964 is about 862.8618218402.

The spelling of 642426964 in words is "six hundred forty-two million, four hundred twenty-six thousand, nine hundred sixty-four".