25961557 has 4 divisors (see below), whose sum is σ = 25992640. Its totient is φ = 25930476.

The previous prime is 25961521. The next prime is 25961563. The reversal of 25961557 is 75516952.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25961557 - 2²³ = 17572949 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 (25961597) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14253 + ... + 15970.

It is an arithmetic number, because the mean of its divisors is an integer number (6498160).

Almost surely, 2^25961557 is an apocalyptic number.

It is an amenable number.

25961557 is a deficient number, since it is larger than the sum of its proper divisors (31083).

25961557 is an equidigital number, since it uses as much as digits as its factorization.

25961557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31082.

The product of its digits is 94500, while the sum is 40.

The square root of 25961557 is about 5095.2484728421. The cubic root of 25961557 is about 296.1035255422.

It can be divided in two parts, 259 and 61557, that added together give a palindrome (61816).

The spelling of 25961557 in words is "twenty-five million, nine hundred sixty-one thousand, five hundred fifty-seven".