255839781 has 16 divisors (see below), whose sum is σ = 346268160. Its totient is φ = 167998320.

The previous prime is 255839777. The next prime is 255839789. The reversal of 255839781 is 187938552.

It is not a de Polignac number, because 255839781 - 2² = 255839777 is a prime.

It is a super-2 number, since 2×255839781² = 130907987084255922, 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 255839781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255839789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93016 + ... + 95726.

It is an arithmetic number, because the mean of its divisors is an integer number (21641760).

Almost surely, 2^255839781 is an apocalyptic number.

It is an amenable number.

255839781 is a deficient number, since it is larger than the sum of its proper divisors (90428379).

255839781 is a wasteful number, since it uses less digits than its factorization.

255839781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3176.

The product of its digits is 604800, while the sum is 48.

The square root of 255839781 is about 15994.9923726146. The cubic root of 255839781 is about 634.8279286592.

The spelling of 255839781 in words is "two hundred fifty-five million, eight hundred thirty-nine thousand, seven hundred eighty-one".