25911561 has 16 divisors (see below), whose sum is σ = 37840320. Its totient is φ = 15673920.

The previous prime is 25911559. The next prime is 25911577. The reversal of 25911561 is 16511952.

It is not a de Polignac number, because 25911561 - 2¹ = 25911559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25911551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3330 + ... + 7931.

It is an arithmetic number, because the mean of its divisors is an integer number (2365020).

Almost surely, 2^25911561 is an apocalyptic number.

It is an amenable number.

25911561 is a deficient number, since it is larger than the sum of its proper divisors (11928759).

25911561 is a wasteful number, since it uses less digits than its factorization.

25911561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11336.

The product of its digits is 2700, while the sum is 30.

The square root of 25911561 is about 5090.3399690001. The cubic root of 25911561 is about 295.9133275882.

The spelling of 25911561 in words is "twenty-five million, nine hundred eleven thousand, five hundred sixty-one".