641191944 has 32 divisors (see below), whose sum is σ = 1646305920. Its totient is φ = 207953856.

The previous prime is 641191913. The next prime is 641191961. The reversal of 641191944 is 449191146.

It is a super-2 number, since 2×641191944² = 822254218100998272, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its 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, 360144 + ... + 361919.

It is an arithmetic number, because the mean of its divisors is an integer number (51447060).

Almost surely, 2^641191944 is an apocalyptic number.

It is an amenable number.

641191944 is an abundant number, since it is smaller than the sum of its proper divisors (1005113976).

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

641191944 is a wasteful number, since it uses less digits than its factorization.

641191944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722109 (or 722105 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 641191944 is about 25321.7681847062. The cubic root of 641191944 is about 862.3085370432.

The spelling of 641191944 in words is "six hundred forty-one million, one hundred ninety-one thousand, nine hundred forty-four".