643406624 has 24 divisors (see below), whose sum is σ = 1447665408. Its totient is φ = 275745600.

The previous prime is 643406593. The next prime is 643406627. The reversal of 643406624 is 426604346.

It is not an unprimeable number, because it can be changed into a prime (643406627) by changing a digit.

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, 1435952 + ... + 1436399.

It is an arithmetic number, because the mean of its divisors is an integer number (60319392).

Almost surely, 2^643406624 is an apocalyptic number.

It is an amenable number.

643406624 is an abundant number, since it is smaller than the sum of its proper divisors (804258784).

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

643406624 is a wasteful number, since it uses less digits than its factorization.

643406624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2872368 (or 2872360 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 35.

The square root of 643406624 is about 25365.4612416175. The cubic root of 643406624 is about 863.3002020980.

The spelling of 643406624 in words is "six hundred forty-three million, four hundred six thousand, six hundred twenty-four".