641976157 has 4 divisors (see below), whose sum is σ = 643150336. Its totient is φ = 640801980.

The previous prime is 641976133. The next prime is 641976163. The reversal of 641976157 is 751679146.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 641976157 - 2⁷ = 641976029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641976187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 586269 + ... + 587362.

It is an arithmetic number, because the mean of its divisors is an integer number (160787584).

Almost surely, 2^641976157 is an apocalyptic number.

It is an amenable number.

641976157 is a deficient number, since it is larger than the sum of its proper divisors (1174179).

641976157 is a wasteful number, since it uses less digits than its factorization.

641976157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1174178.

The product of its digits is 317520, while the sum is 46.

The square root of 641976157 is about 25337.2484101964. The cubic root of 641976157 is about 862.6599440688.

The spelling of 641976157 in words is "six hundred forty-one million, nine hundred seventy-six thousand, one hundred fifty-seven".