256968517 has 24 divisors (see below), whose sum is σ = 291163488. Its totient is φ = 225387360.

The previous prime is 256968511. The next prime is 256968527. The reversal of 256968517 is 715869652.

It is a de Polignac number, because none of the positive numbers 2^k-256968517 is a prime.

It is a super-3 number, since 3×256968517³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256968511) 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 23 ways as a sum of consecutive naturals, for example, 836878 + ... + 837184.

It is an arithmetic number, because the mean of its divisors is an integer number (12131812).

Almost surely, 2^256968517 is an apocalyptic number.

It is an amenable number.

256968517 is a deficient number, since it is larger than the sum of its proper divisors (34194971).

256968517 is a wasteful number, since it uses less digits than its factorization.

256968517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449 (or 418 counting only the distinct ones).

The product of its digits is 907200, while the sum is 49.

The square root of 256968517 is about 16030.2375840160. The cubic root of 256968517 is about 635.7601552344.

The spelling of 256968517 in words is "two hundred fifty-six million, nine hundred sixty-eight thousand, five hundred seventeen".