256738761 has 16 divisors (see below), whose sum is σ = 389632320.
Its totient is φ = 166983840.
The previous prime is 256738753. The next prime is 256738763. The reversal of 256738761 is 167837652.
It can be divided in two parts, 2567 and 38761, that added together give a triangular number (41328 = T287).
256738761 is a `hidden beast` number, since 2 + 567 + 3 + 87 + 6 + 1 = 666.
It is not a de Polignac number, because 256738761 - 23 = 256738753 is a prime.
It is not an unprimeable number, because it can be changed into a prime (256738763) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114855 + ... + 117068.
It is an arithmetic number, because the mean of its divisors is an integer number (24352020).
Almost surely, 2256738761 is an apocalyptic number.
It is an amenable number.
256738761 is a deficient number, since it is larger than the sum of its proper divisors (132893559).
256738761 is a wasteful number, since it uses less digits than its factorization.
256738761 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 231973 (or 231967 counting only the distinct ones).
The product of its digits is 423360, while the sum is 45.
The square root of 256738761 is about 16023.0696497269.
The cubic root of 256738761 is about 635.5706206470.
The spelling of 256738761 in words is "two hundred fifty-six million, seven hundred thirty-eight thousand, seven hundred sixty-one".