256623245476321 has 4 divisors (see below), whose sum is σ = 256810152429972. Its totient is φ = 256436338522672.

The previous prime is 256623245476271. The next prime is 256623245476331. The reversal of 256623245476321 is 123674542326652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 249435779383296 + 7187466093025 = 15793536^2 + 2680945^2 .

It is a cyclic number.

It is not a de Polignac number, because 256623245476321 - 2⁹ = 256623245475809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256623245476331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93453474766 + ... + 93453477511.

It is an arithmetic number, because the mean of its divisors is an integer number (64202538107493).

Almost surely, 2^{256623245476321} is an apocalyptic number.

It is an amenable number.

256623245476321 is a deficient number, since it is larger than the sum of its proper divisors (186906953651).

256623245476321 is a wasteful number, since it uses less digits than its factorization.

256623245476321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186906953650.

The product of its digits is 87091200, while the sum is 58.

The spelling of 256623245476321 in words is "two hundred fifty-six trillion, six hundred twenty-three billion, two hundred forty-five million, four hundred seventy-six thousand, three hundred twenty-one".