256756576221 has 16 divisors (see below), whose sum is σ = 402755414400. Its totient is φ = 161102165184.

The previous prime is 256756576127. The next prime is 256756576301. The reversal of 256756576221 is 122675657652.

256756576221 is a `hidden beast` number, since 2 + 5 + 6 + 7 + 5 + 6 + 5 + 7 + 622 + 1 = 666.

It is not a de Polignac number, because 256756576221 - 2⁷ = 256756576093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256756576721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 279690801 + ... + 279691718.

It is an arithmetic number, because the mean of its divisors is an integer number (25172213400).

Almost surely, 2^256756576221 is an apocalyptic number.

It is an amenable number.

256756576221 is a deficient number, since it is larger than the sum of its proper divisors (145998838179).

256756576221 is a wasteful number, since it uses less digits than its factorization.

256756576221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559382545 (or 559382539 counting only the distinct ones).

The product of its digits is 10584000, while the sum is 54.

The spelling of 256756576221 in words is "two hundred fifty-six billion, seven hundred fifty-six million, five hundred seventy-six thousand, two hundred twenty-one".