255778647 has 4 divisors (see below), whose sum is σ = 341038200. Its totient is φ = 170519096.

The previous prime is 255778643. The next prime is 255778661. The reversal of 255778647 is 746877552.

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

It is a cyclic number.

It is not a de Polignac number, because 255778647 - 2² = 255778643 is a prime.

It is a super-2 number, since 2×255778647² = 130845432522301218, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 255778647.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255778643) 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, 42629772 + ... + 42629777.

It is an arithmetic number, because the mean of its divisors is an integer number (85259550).

Almost surely, 2^255778647 is an apocalyptic number.

255778647 is a deficient number, since it is larger than the sum of its proper divisors (85259553).

255778647 is an equidigital number, since it uses as much as digits as its factorization.

255778647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85259552.

The product of its digits is 3292800, while the sum is 51.

The square root of 255778647 is about 15993.0812228288. The cubic root of 255778647 is about 634.7773596897. Note that the first 3 decimals are identical.

The spelling of 255778647 in words is "two hundred fifty-five million, seven hundred seventy-eight thousand, six hundred forty-seven".