261257 has 8 divisors (see below), whose sum is σ = 280896. Its totient is φ = 242352.

The previous prime is 261251. The next prime is 261271. The reversal of 261257 is 752162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261257 - 2⁴ = 261241 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a nialpdrome in base 8.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 261257.

It is not an unprimeable number, because it can be changed into a prime (261251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 698 + ... + 1004.

It is an arithmetic number, because the mean of its divisors is an integer number (35112).

2²⁶¹²⁵⁷ is an apocalyptic number.

It is an amenable number.

261257 is a deficient number, since it is larger than the sum of its proper divisors (19639).

261257 is a wasteful number, since it uses less digits than its factorization.

261257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367.

The product of its digits is 840, while the sum is 23.

The square root of 261257 is about 511.1330550845. The cubic root of 261257 is about 63.9277341867.

The spelling of 261257 in words is "two hundred sixty-one thousand, two hundred fifty-seven".