643275264 has 40 divisors (see below), whose sum is σ = 1713729600. Its totient is φ = 214424576.

The previous prime is 643275263. The next prime is 643275277. The reversal of 643275264 is 462572346.

It is not an unprimeable number, because it can be changed into a prime (643275263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207864 + ... + 210935.

It is an arithmetic number, because the mean of its divisors is an integer number (42843240).

Almost surely, 2^643275264 is an apocalyptic number.

643275264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

643275264 is an abundant number, since it is smaller than the sum of its proper divisors (1070454336).

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

643275264 is an equidigital number, since it uses as much as digits as its factorization.

643275264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418820 (or 418804 counting only the distinct ones).

The product of its digits is 241920, while the sum is 39.

The square root of 643275264 is about 25362.8717616913. The cubic root of 643275264 is about 863.2414467019.

The spelling of 643275264 in words is "six hundred forty-three million, two hundred seventy-five thousand, two hundred sixty-four".