641939138 has 4 divisors (see below), whose sum is σ = 962908710. Its totient is φ = 320969568.

The previous prime is 641939087. The next prime is 641939141. The reversal of 641939138 is 831939146.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 568202569 + 73736569 = 23837^2 + 8587^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160484783 + ... + 160484786.

Almost surely, 2^641939138 is an apocalyptic number.

641939138 is a deficient number, since it is larger than the sum of its proper divisors (320969572).

641939138 is a wasteful number, since it uses less digits than its factorization.

641939138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320969571.

The product of its digits is 139968, while the sum is 44.

The square root of 641939138 is about 25336.5178744041. The cubic root of 641939138 is about 862.6433622368.

The spelling of 641939138 in words is "six hundred forty-one million, nine hundred thirty-nine thousand, one hundred thirty-eight".