643571255 has 4 divisors (see below), whose sum is σ = 772285512. Its totient is φ = 514857000.

The previous prime is 643571231. The next prime is 643571263. The reversal of 643571255 is 552175346.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 643571255 - 2⁸ = 643570999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64357121 + ... + 64357130.

It is an arithmetic number, because the mean of its divisors is an integer number (193071378).

Almost surely, 2^643571255 is an apocalyptic number.

643571255 is a deficient number, since it is larger than the sum of its proper divisors (128714257).

643571255 is a wasteful number, since it uses less digits than its factorization.

643571255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128714256.

The product of its digits is 126000, while the sum is 38.

The square root of 643571255 is about 25368.7062145471. The cubic root of 643571255 is about 863.3738278321.

The spelling of 643571255 in words is "six hundred forty-three million, five hundred seventy-one thousand, two hundred fifty-five".