255987817 has 4 divisors (see below), whose sum is σ = 269460880. Its totient is φ = 242514756.

The previous prime is 255987791. The next prime is 255987839. The reversal of 255987817 is 718789552.

It is a happy number.

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 255987817 - 2⁷ = 255987689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (255987317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6736503 + ... + 6736540.

It is an arithmetic number, because the mean of its divisors is an integer number (67365220).

Almost surely, 2^255987817 is an apocalyptic number.

It is an amenable number.

255987817 is a deficient number, since it is larger than the sum of its proper divisors (13473063).

255987817 is a wasteful number, since it uses less digits than its factorization.

255987817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13473062.

The product of its digits is 1411200, while the sum is 52.

The square root of 255987817 is about 15999.6192767203. The cubic root of 255987817 is about 634.9503480718.

The spelling of 255987817 in words is "two hundred fifty-five million, nine hundred eighty-seven thousand, eight hundred seventeen".