256749 has 12 divisors (see below), whose sum is σ = 363168. Its totient is φ = 161040.

The previous prime is 256723. The next prime is 256757. The reversal of 256749 is 947652.

It is not a de Polignac number, because 256749 - 2⁸ = 256493 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4179 + ... + 4239.

It is an arithmetic number, because the mean of its divisors is an integer number (30264).

256749 is a Friedman number, since it can be written as 69*(54+7)^2, using all its digits and the basic arithmetic operations.

2²⁵⁶⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

256749 is a deficient number, since it is larger than the sum of its proper divisors (106419).

256749 is an equidigital number, since it uses as much as digits as its factorization.

256749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148 (or 87 counting only the distinct ones).

The product of its digits is 15120, while the sum is 33.

The square root of 256749 is about 506.7040556380. The cubic root of 256749 is about 63.5579069600.

The spelling of 256749 in words is "two hundred fifty-six thousand, seven hundred forty-nine".