257768989 has 2 divisors, whose sum is σ = 257768990. Its totient is φ = 257768988.

The previous prime is 257768983. The next prime is 257769013. The reversal of 257768989 is 989867752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 152028900 + 105740089 = 12330^2 + 10283^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257768989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257768983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128884494 + 128884495.

It is an arithmetic number, because the mean of its divisors is an integer number (128884495).

Almost surely, 2^257768989 is an apocalyptic number.

It is an amenable number.

257768989 is a deficient number, since it is larger than the sum of its proper divisors (1).

257768989 is an equidigital number, since it uses as much as digits as its factorization.

257768989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15240960, while the sum is 61.

The square root of 257768989 is about 16055.1857354563. The cubic root of 257768989 is about 636.4196143454.

The spelling of 257768989 in words is "two hundred fifty-seven million, seven hundred sixty-eight thousand, nine hundred eighty-nine".