256722616947 has 8 divisors (see below), whose sum is σ = 342622513600. Its totient is φ = 170985565800.

The previous prime is 256722616903. The next prime is 256722616973. The reversal of 256722616947 is 749616227652.

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

It is not a de Polignac number, because 256722616947 - 2²² = 256718422643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256722616147) 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, 40707697 + ... + 40714002.

It is an arithmetic number, because the mean of its divisors is an integer number (42827814200).

Almost surely, 2^256722616947 is an apocalyptic number.

256722616947 is a deficient number, since it is larger than the sum of its proper divisors (85899896653).

256722616947 is a wasteful number, since it uses less digits than its factorization.

256722616947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81422753.

The product of its digits is 15240960, while the sum is 57.

The spelling of 256722616947 in words is "two hundred fifty-six billion, seven hundred twenty-two million, six hundred sixteen thousand, nine hundred forty-seven".