256218135688301 has 2 divisors, whose sum is σ = 256218135688302. Its totient is φ = 256218135688300.

The previous prime is 256218135688261. The next prime is 256218135688303. The reversal of 256218135688301 is 103886531812652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 245324901448201 + 10893234240100 = 15662851^2 + 3300490^2 .

It is a cyclic number.

It is not a de Polignac number, because 256218135688301 - 2¹⁰ = 256218135687277 is a prime.

Together with 256218135688303, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256218135688303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128109067844150 + 128109067844151.

It is an arithmetic number, because the mean of its divisors is an integer number (128109067844151).

Almost surely, 2^{256218135688301} is an apocalyptic number.

It is an amenable number.

256218135688301 is a deficient number, since it is larger than the sum of its proper divisors (1).

256218135688301 is an equidigital number, since it uses as much as digits as its factorization.

256218135688301 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16588800, while the sum is 59.

The spelling of 256218135688301 in words is "two hundred fifty-six trillion, two hundred eighteen billion, one hundred thirty-five million, six hundred eighty-eight thousand, three hundred one".