255905689 has 4 divisors (see below), whose sum is σ = 275590756. Its totient is φ = 236220624.

The previous prime is 255905687. The next prime is 255905701. The reversal of 255905689 is 986509552.

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

It can be written as a sum of positive squares in 2 ways, for example, as 110944089 + 144961600 = 10533^2 + 12040^2 .

It is a cyclic number.

It is not a de Polignac number, because 255905689 - 2¹ = 255905687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (255905681) 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, 9842514 + ... + 9842539.

It is an arithmetic number, because the mean of its divisors is an integer number (68897689).

Almost surely, 2^255905689 is an apocalyptic number.

It is an amenable number.

255905689 is a deficient number, since it is larger than the sum of its proper divisors (19685067).

255905689 is a wasteful number, since it uses less digits than its factorization.

255905689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19685066.

The product of its (nonzero) digits is 972000, while the sum is 49.

The square root of 255905689 is about 15997.0525097594. The cubic root of 255905689 is about 634.8824375744.

The spelling of 255905689 in words is "two hundred fifty-five million, nine hundred five thousand, six hundred eighty-nine".