1256655121 has 8 divisors (see below), whose sum is σ = 1284480000. Its totient is φ = 1228875648.

The previous prime is 1256655077. The next prime is 1256655151. The reversal of 1256655121 is 1215566521.

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 1256655121 - 2²⁵ = 1223100689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1256655151) 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, 48000 + ... + 69406.

It is an arithmetic number, because the mean of its divisors is an integer number (160560000).

Almost surely, 2^1256655121 is an apocalyptic number.

It is an amenable number.

1256655121 is a deficient number, since it is larger than the sum of its proper divisors (27824879).

1256655121 is a wasteful number, since it uses less digits than its factorization.

1256655121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22703.

The product of its digits is 18000, while the sum is 34.

The square root of 1256655121 is about 35449.3317426436. The cubic root of 1256655121 is about 1079.1256987322.

The spelling of 1256655121 in words is "one billion, two hundred fifty-six million, six hundred fifty-five thousand, one hundred twenty-one".