256124517581 has 8 divisors (see below), whose sum is σ = 271199594304. Its totient is φ = 241050432960.

The previous prime is 256124517569. The next prime is 256124517599. The reversal of 256124517581 is 185715421652.

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

It is a cyclic number.

It is not a de Polignac number, because 256124517581 - 2³⁰ = 255050775757 is a prime.

It is a super-3 number, since 3×256124517581³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256124517521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 320786 + ... + 784316.

It is an arithmetic number, because the mean of its divisors is an integer number (33899949288).

Almost surely, 2^256124517581 is an apocalyptic number.

It is an amenable number.

256124517581 is a deficient number, since it is larger than the sum of its proper divisors (15075076723).

256124517581 is a wasteful number, since it uses less digits than its factorization.

256124517581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496051.

The product of its digits is 672000, while the sum is 47.

The spelling of 256124517581 in words is "two hundred fifty-six billion, one hundred twenty-four million, five hundred seventeen thousand, five hundred eighty-one".