641571864 has 16 divisors (see below), whose sum is σ = 1603929720. Its totient is φ = 213857280.

The previous prime is 641571863. The next prime is 641571899. The reversal of 641571864 is 468175146.

It is a super-2 number, since 2×641571864² = 823228913352868992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641571863) 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, 13366057 + ... + 13366104.

Almost surely, 2^641571864 is an apocalyptic number.

It is an amenable number.

641571864 is an abundant number, since it is smaller than the sum of its proper divisors (962357856).

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

641571864 is a wasteful number, since it uses less digits than its factorization.

641571864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26732170 (or 26732166 counting only the distinct ones).

The product of its digits is 161280, while the sum is 42.

The square root of 641571864 is about 25329.2689195721. The cubic root of 641571864 is about 862.4788155267.

The spelling of 641571864 in words is "six hundred forty-one million, five hundred seventy-one thousand, eight hundred sixty-four".