255691009 has 4 divisors (see below), whose sum is σ = 292218304. Its totient is φ = 219163716.

The previous prime is 255690997. The next prime is 255691013. The reversal of 255691009 is 900196552.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 255691009 - 2⁷ = 255690881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (255691019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18263637 + ... + 18263650.

It is an arithmetic number, because the mean of its divisors is an integer number (73054576).

Almost surely, 2^255691009 is an apocalyptic number.

It is an amenable number.

255691009 is a deficient number, since it is larger than the sum of its proper divisors (36527295).

255691009 is an equidigital number, since it uses as much as digits as its factorization.

255691009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36527294.

The product of its (nonzero) digits is 24300, while the sum is 37.

The square root of 255691009 is about 15990.3411158111. The cubic root of 255691009 is about 634.7048530207.

The spelling of 255691009 in words is "two hundred fifty-five million, six hundred ninety-one thousand, nine".