256513173 has 8 divisors (see below), whose sum is σ = 390877248. Its totient is φ = 146578944.

The previous prime is 256513171. The next prime is 256513177. The reversal of 256513173 is 371315652.

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

It is not a de Polignac number, because 256513173 - 2¹ = 256513171 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256513171) 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 7 ways as a sum of consecutive naturals, for example, 6107436 + ... + 6107477.

It is an arithmetic number, because the mean of its divisors is an integer number (48859656).

Almost surely, 2^256513173 is an apocalyptic number.

It is an amenable number.

256513173 is a deficient number, since it is larger than the sum of its proper divisors (134364075).

256513173 is a wasteful number, since it uses less digits than its factorization.

256513173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12214923.

The product of its digits is 18900, while the sum is 33.

The square root of 256513173 is about 16016.0286275968. The cubic root of 256513173 is about 635.3844143534.

It can be divided in two parts, 256513 and 173, that added together give a triangular number (256686 = T₇₁₆).

The spelling of 256513173 in words is "two hundred fifty-six million, five hundred thirteen thousand, one hundred seventy-three".