255491865 has 24 divisors (see below), whose sum is σ = 444804360. Its totient is φ = 135661824.

The previous prime is 255491839. The next prime is 255491893. The reversal of 255491865 is 568194552.

255491865 is a `hidden beast` number, since 2 + 554 + 91 + 8 + 6 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 156350016 + 99141849 = 12504^2 + 9957^2 .

It is not a de Polignac number, because 255491865 - 2⁷ = 255491737 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 255491865.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2092 + ... + 22701.

It is an arithmetic number, because the mean of its divisors is an integer number (18533515).

Almost surely, 2^255491865 is an apocalyptic number.

It is an amenable number.

255491865 is a deficient number, since it is larger than the sum of its proper divisors (189312495).

255491865 is a wasteful number, since it uses less digits than its factorization.

255491865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25033 (or 25030 counting only the distinct ones).

The product of its digits is 432000, while the sum is 45.

The square root of 255491865 is about 15984.1128937455. The cubic root of 255491865 is about 634.5400310445.

The spelling of 255491865 in words is "two hundred fifty-five million, four hundred ninety-one thousand, eight hundred sixty-five".