25561513 has 4 divisors (see below), whose sum is σ = 25578180. Its totient is φ = 25544848.

The previous prime is 25561511. The next prime is 25561519. The reversal of 25561513 is 31516552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5607424 + 19954089 = 2368^2 + 4467^2 .

It is a cyclic number.

It is not a de Polignac number, because 25561513 - 2¹ = 25561511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25561511) 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, 5770 + ... + 9187.

It is an arithmetic number, because the mean of its divisors is an integer number (6394545).

Almost surely, 2^25561513 is an apocalyptic number.

It is an amenable number.

25561513 is a deficient number, since it is larger than the sum of its proper divisors (16667).

25561513 is a wasteful number, since it uses less digits than its factorization.

25561513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16666.

The product of its digits is 4500, while the sum is 28.

The square root of 25561513 is about 5055.8394950789. The cubic root of 25561513 is about 294.5747506892.

The spelling of 25561513 in words is "twenty-five million, five hundred sixty-one thousand, five hundred thirteen".