643240255 has 16 divisors (see below), whose sum is σ = 882814464. Its totient is φ = 440750880.

The previous prime is 643240229. The next prime is 643240319. The reversal of 643240255 is 552042346.

It is not a de Polignac number, because 643240255 - 2⁵ = 643240223 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46804 + ... + 58966.

It is an arithmetic number, because the mean of its divisors is an integer number (55175904).

Almost surely, 2^643240255 is an apocalyptic number.

643240255 is a deficient number, since it is larger than the sum of its proper divisors (239574209).

643240255 is a wasteful number, since it uses less digits than its factorization.

643240255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13686.

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 643240255 is about 25362.1815899185. The cubic root of 643240255 is about 863.2257863412.

The spelling of 643240255 in words is "six hundred forty-three million, two hundred forty thousand, two hundred fifty-five".