257540781077 has 2 divisors, whose sum is σ = 257540781078. Its totient is φ = 257540781076.

The previous prime is 257540781067. The next prime is 257540781109. The reversal of 257540781077 is 770187045752.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 257098688401 + 442092676 = 507049^2 + 21026^2 .

It is a cyclic number.

It is not a de Polignac number, because 257540781077 - 2¹⁸ = 257540518933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257540781067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128770390538 + 128770390539.

It is an arithmetic number, because the mean of its divisors is an integer number (128770390539).

Almost surely, 2^257540781077 is an apocalyptic number.

It is an amenable number.

257540781077 is a deficient number, since it is larger than the sum of its proper divisors (1).

257540781077 is an equidigital number, since it uses as much as digits as its factorization.

257540781077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3841600, while the sum is 53.

The spelling of 257540781077 in words is "two hundred fifty-seven billion, five hundred forty million, seven hundred eighty-one thousand, seventy-seven".