643564374 has 8 divisors (see below), whose sum is σ = 1287128760. Its totient is φ = 214521456.

The previous prime is 643564351. The next prime is 643564379. The reversal of 643564374 is 473465346.

It is a sphenic number, since it is the product of 3 distinct primes.

643564374 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643564379) 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, 53630359 + ... + 53630370.

It is an arithmetic number, because the mean of its divisors is an integer number (160891095).

Almost surely, 2^643564374 is an apocalyptic number.

643564374 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

643564374 is a wasteful number, since it uses less digits than its factorization.

643564374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107260734.

The product of its digits is 725760, while the sum is 42.

The square root of 643564374 is about 25368.5705943398. The cubic root of 643564374 is about 863.3707507854.

The spelling of 643564374 in words is "six hundred forty-three million, five hundred sixty-four thousand, three hundred seventy-four".