256121755 has 8 divisors (see below), whose sum is σ = 308666592. Its totient is φ = 204017088.

The previous prime is 256121693. The next prime is 256121777. The reversal of 256121755 is 557121652.

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 256121755 - 2⁷ = 256121627 is a prime.

It is a super-3 number, since 3×256121755³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256121755.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108759 + ... + 111088.

It is an arithmetic number, because the mean of its divisors is an integer number (38583324).

Almost surely, 2^256121755 is an apocalyptic number.

256121755 is a deficient number, since it is larger than the sum of its proper divisors (52544837).

256121755 is a wasteful number, since it uses less digits than its factorization.

256121755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220085.

The product of its digits is 21000, while the sum is 34.

The square root of 256121755 is about 16003.8043914564. The cubic root of 256121755 is about 635.0610683823.

The spelling of 256121755 in words is "two hundred fifty-six million, one hundred twenty-one thousand, seven hundred fifty-five".