640443546 has 48 divisors (see below), whose sum is σ = 1404936000. Its totient is φ = 210833280.

The previous prime is 640443481. The next prime is 640443581. The reversal of 640443546 is 645344046.

640443546 is a `hidden beast` number, since 640 + 4 + 4 + 3 + 5 + 4 + 6 = 666.

It is a super-2 number, since 2×640443546² = 820335871226108232, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640443546.

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 23 ways as a sum of consecutive naturals, for example, 1014651 + ... + 1015281.

It is an arithmetic number, because the mean of its divisors is an integer number (29269500).

Almost surely, 2^640443546 is an apocalyptic number.

640443546 is an abundant number, since it is smaller than the sum of its proper divisors (764492454).

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

640443546 is a wasteful number, since it uses less digits than its factorization.

640443546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1251 (or 1248 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

The square root of 640443546 is about 25306.9861105585. The cubic root of 640443546 is about 861.9729114752.

The spelling of 640443546 in words is "six hundred forty million, four hundred forty-three thousand, five hundred forty-six".