641915791 has 32 divisors (see below), whose sum is σ = 742680576. Its totient is φ = 549504000.

The previous prime is 641915753. The next prime is 641915831. The reversal of 641915791 is 197519146.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 641915791 - 2²¹ = 639818639 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641915731) 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, 2663431 + ... + 2663671.

It is an arithmetic number, because the mean of its divisors is an integer number (23208768).

Almost surely, 2^641915791 is an apocalyptic number.

641915791 is a deficient number, since it is larger than the sum of its proper divisors (100764785).

641915791 is a wasteful number, since it uses less digits than its factorization.

641915791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463.

The product of its digits is 68040, while the sum is 43.

The square root of 641915791 is about 25336.0571320796. The cubic root of 641915791 is about 862.6329041432.

The spelling of 641915791 in words is "six hundred forty-one million, nine hundred fifteen thousand, seven hundred ninety-one".