641886720 has 80 divisors (see below), whose sum is σ = 2052056160. Its totient is φ = 171167744.

The previous prime is 641886701. The next prime is 641886743. The reversal of 641886720 is 27688146.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×641886720² = 824037122624716800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34110 + ... + 49469.

It is an arithmetic number, because the mean of its divisors is an integer number (25650702).

Almost surely, 2^641886720 is an apocalyptic number.

641886720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

641886720 is an abundant number, since it is smaller than the sum of its proper divisors (1410169440).

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

641886720 is an equidigital number, since it uses as much as digits as its factorization.

641886720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83605 (or 83589 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 641886720 is about 25335.4834175312. The cubic root of 641886720 is about 862.6198816772.

The spelling of 641886720 in words is "six hundred forty-one million, eight hundred eighty-six thousand, seven hundred twenty".