255999999 has 8 divisors (see below), whose sum is σ = 341418672. Its totient is φ = 170624000.

The previous prime is 255999983. The next prime is 256000001. The reversal of 255999999 is 999999552.

It is a Cunningham number, because it is equal to 16000²-1.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 255999999 - 2⁴ = 255999983 is a prime.

255999999 is a modest number, since divided by 99999 gives 2559 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255999949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7999 + ... + 23999.

It is an arithmetic number, because the mean of its divisors is an integer number (42677334).

Almost surely, 2^255999999 is an apocalyptic number.

255999999 is a deficient number, since it is larger than the sum of its proper divisors (85418673).

255999999 is a wasteful number, since it uses less digits than its factorization.

255999999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21337.

The product of its digits is 26572050, while the sum is 66.

The square root of 255999999 is about 15999.9999687500. Note that the first 4 decimals coincide. The cubic root of 255999999 is about 634.9604199605.

The spelling of 255999999 in words is "two hundred fifty-five million, nine hundred ninety-nine thousand, nine hundred ninety-nine".