25510561 has 2 divisors, whose sum is σ = 25510562. Its totient is φ = 25510560.

The previous prime is 25510553. The next prime is 25510577. The reversal of 25510561 is 16501552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14745600 + 10764961 = 3840^2 + 3281^2 .

It is a cyclic number.

It is not a de Polignac number, because 25510561 - 2³ = 25510553 is a prime.

It is not a weakly prime, because it can be changed into another prime (25550561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12755280 + 12755281.

It is an arithmetic number, because the mean of its divisors is an integer number (12755281).

Almost surely, 2^25510561 is an apocalyptic number.

It is an amenable number.

25510561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25510561 is an equidigital number, since it uses as much as digits as its factorization.

25510561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 25510561 is about 5050.7980557532. The cubic root of 25510561 is about 294.3788943068.

Subtracting from 25510561 its reverse (16501552), we obtain a palindrome (9009009).

It can be divided in two parts, 255 and 10561, that added together give a square (10816 = 104²).

The spelling of 25510561 in words is "twenty-five million, five hundred ten thousand, five hundred sixty-one".