257165649 has 24 divisors (see below), whose sum is σ = 413835240. Its totient is φ = 152796672.

The previous prime is 257165639. The next prime is 257165659. The reversal of 257165649 is 946561752.

It is an interprime number because it is at equal distance from previous prime (257165639) and next prime (257165659).

It can be written as a sum of positive squares in 4 ways, for example, as 33872400 + 223293249 = 5820^2 + 14943^2 .

It is not a de Polignac number, because 257165649 - 2⁵ = 257165617 is a prime.

It is a super-2 number, since 2×257165649² = 132268342051182402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (257165609) 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, 34504 + ... + 41289.

It is an arithmetic number, because the mean of its divisors is an integer number (17243135).

Almost surely, 2^257165649 is an apocalyptic number.

257165649 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

257165649 is a deficient number, since it is larger than the sum of its proper divisors (156669591).

257165649 is a wasteful number, since it uses less digits than its factorization.

257165649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75841 (or 75838 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The square root of 257165649 is about 16036.3851600041. The cubic root of 257165649 is about 635.9226869947.

The spelling of 257165649 in words is "two hundred fifty-seven million, one hundred sixty-five thousand, six hundred forty-nine".