256575761521 has 8 divisors (see below), whose sum is σ = 259530480000. Its totient is φ = 253631967120.

The previous prime is 256575761513. The next prime is 256575761551. The reversal of 256575761521 is 125167575652.

It is a happy number.

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 256575761521 - 2³ = 256575761513 is a prime.

It is a super-2 number, since 2×256575761521² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256575761551) 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, 2683771 + ... + 2777728.

It is an arithmetic number, because the mean of its divisors is an integer number (32441310000).

Almost surely, 2^256575761521 is an apocalyptic number.

It is an amenable number.

256575761521 is a deficient number, since it is larger than the sum of its proper divisors (2954718479).

256575761521 is a wasteful number, since it uses less digits than its factorization.

256575761521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5462039.

The product of its digits is 4410000, while the sum is 52.

The spelling of 256575761521 in words is "two hundred fifty-six billion, five hundred seventy-five million, seven hundred sixty-one thousand, five hundred twenty-one".