256667135561701 has 2 divisors, whose sum is σ = 256667135561702. Its totient is φ = 256667135561700.

The previous prime is 256667135561611. The next prime is 256667135561713. The reversal of 256667135561701 is 107165531766652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181205790012900 + 75461345548801 = 13461270^2 + 8686849^2 .

It is a cyclic number.

It is not a de Polignac number, because 256667135561701 - 2²¹ = 256667133464549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256667135561701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256667135562701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128333567780850 + 128333567780851.

It is an arithmetic number, because the mean of its divisors is an integer number (128333567780851).

Almost surely, 2^{256667135561701} is an apocalyptic number.

It is an amenable number.

256667135561701 is a deficient number, since it is larger than the sum of its proper divisors (1).

256667135561701 is an equidigital number, since it uses as much as digits as its factorization.

256667135561701 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47628000, while the sum is 61.

The spelling of 256667135561701 in words is "two hundred fifty-six trillion, six hundred sixty-seven billion, one hundred thirty-five million, five hundred sixty-one thousand, seven hundred one".