642641625 has 48 divisors (see below), whose sum is σ = 1195903488. Its totient is φ = 331668000.

The previous prime is 642641611. The next prime is 642641627. The reversal of 642641625 is 526146246.

642641625 is a `hidden beast` number, since 6 + 4 + 2 + 641 + 6 + 2 + 5 = 666.

It is not a de Polignac number, because 642641625 - 2⁴ = 642641609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642641625.

It is not an unprimeable number, because it can be changed into a prime (642641627) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25662 + ... + 44088.

It is an arithmetic number, because the mean of its divisors is an integer number (24914656).

Almost surely, 2^642641625 is an apocalyptic number.

It is an amenable number.

642641625 is a deficient number, since it is larger than the sum of its proper divisors (553261863).

642641625 is a wasteful number, since it uses less digits than its factorization.

642641625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18479 (or 18466 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 642641625 is about 25350.3772161284. The cubic root of 642641625 is about 862.9579168910.

The spelling of 642641625 in words is "six hundred forty-two million, six hundred forty-one thousand, six hundred twenty-five".