256742109 has 48 divisors (see below), whose sum is σ = 435301440. Its totient is φ = 148642560.

The previous prime is 256742069. The next prime is 256742111. The reversal of 256742109 is 901247652.

It is not a de Polignac number, because 256742109 - 2¹¹ = 256740061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256742119) 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 47 ways as a sum of consecutive naturals, for example, 100174 + ... + 102704.

It is an arithmetic number, because the mean of its divisors is an integer number (9068780).

Almost surely, 2^256742109 is an apocalyptic number.

It is an amenable number.

256742109 is a deficient number, since it is larger than the sum of its proper divisors (178559331).

256742109 is a wasteful number, since it uses less digits than its factorization.

256742109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2587 (or 2564 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 256742109 is about 16023.1741237496. The cubic root of 256742109 is about 635.5733833530.

The spelling of 256742109 in words is "two hundred fifty-six million, seven hundred forty-two thousand, one hundred nine".