641449940 has 48 divisors (see below), whose sum is σ = 1359880704. Its totient is φ = 254150400.

The previous prime is 641449903. The next prime is 641449951. The reversal of 641449940 is 49944146.

It is a happy number.

It is a super-2 number, since 2×641449940² = 822916051052007200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1747637 + ... + 1748003.

It is an arithmetic number, because the mean of its divisors is an integer number (28330848).

Almost surely, 2^641449940 is an apocalyptic number.

It is an amenable number.

641449940 is an abundant number, since it is smaller than the sum of its proper divisors (718430764).

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

641449940 is a wasteful number, since it uses less digits than its factorization.

641449940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968 (or 966 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 641449940 is about 25326.8620243409. The cubic root of 641449940 is about 862.4241770495.

The spelling of 641449940 in words is "six hundred forty-one million, four hundred forty-nine thousand, nine hundred forty".