256193724721 has 8 divisors (see below), whose sum is σ = 281684726784. Its totient is φ = 231069499920.

The previous prime is 256193724691. The next prime is 256193724727. The reversal of 256193724721 is 127427391652.

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 256193724721 - 2¹³ = 256193716529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256193724727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91692850 + ... + 91695643.

It is an arithmetic number, because the mean of its divisors is an integer number (35210590848).

Almost surely, 2^256193724721 is an apocalyptic number.

It is an amenable number.

256193724721 is a deficient number, since it is larger than the sum of its proper divisors (25491002063).

256193724721 is a wasteful number, since it uses less digits than its factorization.

256193724721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183388631.

The product of its digits is 1270080, while the sum is 49.

The spelling of 256193724721 in words is "two hundred fifty-six billion, one hundred ninety-three million, seven hundred twenty-four thousand, seven hundred twenty-one".