641278188 has 24 divisors (see below), whose sum is σ = 1662573360. Its totient is φ = 213759360.

The previous prime is 641278153. The next prime is 641278207. The reversal of 641278188 is 881872146.

It is a super-2 number, since 2×641278188² = 822475428809126688, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2968773 + ... + 2968988.

It is an arithmetic number, because the mean of its divisors is an integer number (69273890).

Almost surely, 2^641278188 is an apocalyptic number.

It is an amenable number.

641278188 is an abundant number, since it is smaller than the sum of its proper divisors (1021295172).

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

641278188 is a wasteful number, since it uses less digits than its factorization.

641278188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5937774 (or 5937766 counting only the distinct ones).

The product of its digits is 172032, while the sum is 45.

The square root of 641278188 is about 25323.4710890905. The cubic root of 641278188 is about 862.3471971272.

The spelling of 641278188 in words is "six hundred forty-one million, two hundred seventy-eight thousand, one hundred eighty-eight".