641971538 has 64 divisors (see below), whose sum is σ = 1114767360. Its totient is φ = 275026752.

The previous prime is 641971537. The next prime is 641971549. The reversal of 641971538 is 835179146.

It is not an unprimeable number, because it can be changed into a prime (641971531) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5054831 + ... + 5054957.

It is an arithmetic number, because the mean of its divisors is an integer number (17418240).

Almost surely, 2^641971538 is an apocalyptic number.

641971538 is a deficient number, since it is larger than the sum of its proper divisors (472795822).

641971538 is a wasteful number, since it uses less digits than its factorization.

641971538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351.

The product of its digits is 181440, while the sum is 44.

The square root of 641971538 is about 25337.1572596454. The cubic root of 641971538 is about 862.6578751260.

The spelling of 641971538 in words is "six hundred forty-one million, nine hundred seventy-one thousand, five hundred thirty-eight".