256628780026357 has 2 divisors, whose sum is σ = 256628780026358. Its totient is φ = 256628780026356.

The previous prime is 256628780026321. The next prime is 256628780026361. The reversal of 256628780026357 is 753620087826652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 224393479293361 + 32235300732996 = 14979769^2 + 5677614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256628780026357 is a prime.

It is a super-2 number, since 2×256628780026357² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256628780026292 and 256628780026301.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256628780026057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128314390013178 + 128314390013179.

It is an arithmetic number, because the mean of its divisors is an integer number (128314390013179).

Almost surely, 2^{256628780026357} is an apocalyptic number.

It is an amenable number.

256628780026357 is a deficient number, since it is larger than the sum of its proper divisors (1).

256628780026357 is an equidigital number, since it uses as much as digits as its factorization.

256628780026357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 406425600, while the sum is 67.

The spelling of 256628780026357 in words is "two hundred fifty-six trillion, six hundred twenty-eight billion, seven hundred eighty million, twenty-six thousand, three hundred fifty-seven".