642725538 has 32 divisors (see below), whose sum is σ = 1582094976. Its totient is φ = 169509888.

The previous prime is 642725509. The next prime is 642725549. The reversal of 642725538 is 835527246.

642725538 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×642725538² = 826192234394778888, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 642725538.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 588031 + ... + 589122.

It is an arithmetic number, because the mean of its divisors is an integer number (49440468).

Almost surely, 2^642725538 is an apocalyptic number.

642725538 is an abundant number, since it is smaller than the sum of its proper divisors (939369438).

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

642725538 is a wasteful number, since it uses less digits than its factorization.

642725538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177178.

The product of its digits is 403200, while the sum is 42.

The square root of 642725538 is about 25352.0322262339. The cubic root of 642725538 is about 862.9954755309.

The spelling of 642725538 in words is "six hundred forty-two million, seven hundred twenty-five thousand, five hundred thirty-eight".