25561409 has 8 divisors (see below), whose sum is σ = 26289312. Its totient is φ = 24838560.

The previous prime is 25561369. The next prime is 25561411. The reversal of 25561409 is 90416552.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25561409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25561439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10502 + ... + 12704.

It is an arithmetic number, because the mean of its divisors is an integer number (3286164).

Almost surely, 2^25561409 is an apocalyptic number.

It is an amenable number.

25561409 is a deficient number, since it is larger than the sum of its proper divisors (727903).

25561409 is a wasteful number, since it uses less digits than its factorization.

25561409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2527.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 25561409 is about 5055.8292099318. The cubic root of 25561409 is about 294.5743511847.

The spelling of 25561409 in words is "twenty-five million, five hundred sixty-one thousand, four hundred nine".