255681990 has 24 divisors (see below), whose sum is σ = 664773408. Its totient is φ = 68181840.

The previous prime is 255681977. The next prime is 255681997. The reversal of 255681990 is 99186552.

255681990 is a `hidden beast` number, since 2 + 556 + 8 + 1 + 9 + 90 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255681997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1420366 + ... + 1420545.

It is an arithmetic number, because the mean of its divisors is an integer number (27698892).

Almost surely, 2^255681990 is an apocalyptic number.

255681990 is an abundant number, since it is smaller than the sum of its proper divisors (409091418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

255681990 is a wasteful number, since it uses less digits than its factorization.

255681990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2840924 (or 2840921 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The square root of 255681990 is about 15990.0590993279. The cubic root of 255681990 is about 634.6973902758.

The spelling of 255681990 in words is "two hundred fifty-five million, six hundred eighty-one thousand, nine hundred ninety".