256661226321 has 8 divisors (see below), whose sum is σ = 342230888640. Its totient is φ = 171099524112.

The previous prime is 256661226299. The next prime is 256661226323. The reversal of 256661226321 is 123622166652.

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

It is not a de Polignac number, because 256661226321 - 2⁷ = 256661226193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256661226323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1914381 + ... + 2044058.

It is an arithmetic number, because the mean of its divisors is an integer number (42778861080).

Almost surely, 2^256661226321 is an apocalyptic number.

It is an amenable number.

256661226321 is a deficient number, since it is larger than the sum of its proper divisors (85569662319).

256661226321 is a wasteful number, since it uses less digits than its factorization.

256661226321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980055.

The product of its digits is 311040, while the sum is 42.

The spelling of 256661226321 in words is "two hundred fifty-six billion, six hundred sixty-one million, two hundred twenty-six thousand, three hundred twenty-one".