641475440 has 20 divisors (see below), whose sum is σ = 1491430584. Its totient is φ = 256590144.

The previous prime is 641475437. The next prime is 641475479. The reversal of 641475440 is 44574146.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×641475440² = 822981480246387200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 641475440.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 4009142 + ... + 4009301.

Almost surely, 2^641475440 is an apocalyptic number.

It is an amenable number.

641475440 is an abundant number, since it is smaller than the sum of its proper divisors (849955144).

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

641475440 is a wasteful number, since it uses less digits than its factorization.

641475440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8018456 (or 8018450 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 35.

The square root of 641475440 is about 25327.3654374078. The cubic root of 641475440 is about 862.4356050782.

The spelling of 641475440 in words is "six hundred forty-one million, four hundred seventy-five thousand, four hundred forty".