257129509 has 24 divisors (see below), whose sum is σ = 325328640. Its totient is φ = 201416544.

The previous prime is 257129507. The next prime is 257129519. The reversal of 257129509 is 905921752.

It is not a de Polignac number, because 257129509 - 2¹ = 257129507 is a prime.

It is a super-2 number, since 2×257129509² = 132231168797162162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257129501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63652 + ... + 67570.

It is an arithmetic number, because the mean of its divisors is an integer number (13555360).

Almost surely, 2^257129509 is an apocalyptic number.

It is an amenable number.

257129509 is a deficient number, since it is larger than the sum of its proper divisors (68199131).

257129509 is a wasteful number, since it uses less digits than its factorization.

257129509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4049 (or 4042 counting only the distinct ones).

The product of its (nonzero) digits is 56700, while the sum is 40.

The square root of 257129509 is about 16035.2583078664. The cubic root of 257129509 is about 635.8928964392.

The spelling of 257129509 in words is "two hundred fifty-seven million, one hundred twenty-nine thousand, five hundred nine".