25857261 has 6 divisors (see below), whose sum is σ = 37349390. Its totient is φ = 17238168.

The previous prime is 25857217. The next prime is 25857263. The reversal of 25857261 is 16275852.

It is a happy number.

25857261 is a `hidden beast` number, since 2 + 585 + 72 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 25857225 + 36 = 5085^2 + 6^2 .

It is not a de Polignac number, because 25857261 - 2⁷ = 25857133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25857263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1436506 + ... + 1436523.

Almost surely, 2^25857261 is an apocalyptic number.

It is an amenable number.

25857261 is a deficient number, since it is larger than the sum of its proper divisors (11492129).

25857261 is a wasteful number, since it uses less digits than its factorization.

25857261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2873035 (or 2873032 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 25857261 is about 5085.0035398218. The cubic root of 25857261 is about 295.7064787249.

Subtracting from 25857261 its sum of digits (36), we obtain a square (25857225 = 5085²).

The spelling of 25857261 in words is "twenty-five million, eight hundred fifty-seven thousand, two hundred sixty-one".