256144406569 has 2 divisors, whose sum is σ = 256144406570. Its totient is φ = 256144406568.

The previous prime is 256144406549. The next prime is 256144406627. The reversal of 256144406569 is 965604441652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141084374544 + 115060032025 = 375612^2 + 339205^2 .

It is a cyclic number.

It is not a de Polignac number, because 256144406569 - 2³³ = 247554471977 is a prime.

It is a super-2 number, since 2×256144406569² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256144406549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128072203284 + 128072203285.

It is an arithmetic number, because the mean of its divisors is an integer number (128072203285).

Almost surely, 2^256144406569 is an apocalyptic number.

It is an amenable number.

256144406569 is a deficient number, since it is larger than the sum of its proper divisors (1).

256144406569 is an equidigital number, since it uses as much as digits as its factorization.

256144406569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6220800, while the sum is 52.

The spelling of 256144406569 in words is "two hundred fifty-six billion, one hundred forty-four million, four hundred six thousand, five hundred sixty-nine".