255991739 has 4 divisors (see below), whose sum is σ = 257406240. Its totient is φ = 254577240.

The previous prime is 255991727. The next prime is 255991753. The reversal of 255991739 is 937199552.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-255991739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (255991709) 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 3 ways as a sum of consecutive naturals, for example, 706979 + ... + 707340.

It is an arithmetic number, because the mean of its divisors is an integer number (64351560).

Almost surely, 2^255991739 is an apocalyptic number.

255991739 is a deficient number, since it is larger than the sum of its proper divisors (1414501).

255991739 is a wasteful number, since it uses less digits than its factorization.

255991739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1414500.

The product of its digits is 765450, while the sum is 50.

The square root of 255991739 is about 15999.7418416673. The cubic root of 255991739 is about 634.9535907554.

The spelling of 255991739 in words is "two hundred fifty-five million, nine hundred ninety-one thousand, seven hundred thirty-nine".