255639865 has 8 divisors (see below), whose sum is σ = 330365448. Its totient is φ = 188780160.

The previous prime is 255639833. The next prime is 255639877. The reversal of 255639865 is 568936552.

It can be written as a sum of positive squares in 4 ways, for example, as 35176761 + 220463104 = 5931^2 + 14848^2 .

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

It is not a de Polignac number, because 255639865 - 2⁵ = 255639833 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1966396 + ... + 1966525.

It is an arithmetic number, because the mean of its divisors is an integer number (41295681).

Almost surely, 2^255639865 is an apocalyptic number.

It is an amenable number.

255639865 is a deficient number, since it is larger than the sum of its proper divisors (74725583).

255639865 is a wasteful number, since it uses less digits than its factorization.

255639865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3932939.

The product of its digits is 1944000, while the sum is 49.

The square root of 255639865 is about 15988.7418204185. The cubic root of 255639865 is about 634.6625317443.

The spelling of 255639865 in words is "two hundred fifty-five million, six hundred thirty-nine thousand, eight hundred sixty-five".