257105509 has 2 divisors, whose sum is σ = 257105510. Its totient is φ = 257105508.

The previous prime is 257105483. The next prime is 257105533. The reversal of 257105509 is 905501752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 255296484 + 1809025 = 15978^2 + 1345^2 .

It is a cyclic number.

It is not a de Polignac number, because 257105509 - 2⁹ = 257104997 is a prime.

It is a super-2 number, since 2×257105509² = 132206485516298162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257135509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128552754 + 128552755.

It is an arithmetic number, because the mean of its divisors is an integer number (128552755).

Almost surely, 2^257105509 is an apocalyptic number.

It is an amenable number.

257105509 is a deficient number, since it is larger than the sum of its proper divisors (1).

257105509 is an equidigital number, since it uses as much as digits as its factorization.

257105509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15750, while the sum is 34.

The square root of 257105509 is about 16034.5099395024. The cubic root of 257105509 is about 635.8731114621.

The spelling of 257105509 in words is "two hundred fifty-seven million, one hundred five thousand, five hundred nine".