25684661 has 4 divisors (see below), whose sum is σ = 25704300. Its totient is φ = 25665024.

The previous prime is 25684657. The next prime is 25684667. The reversal of 25684661 is 16648652.

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 13912900 + 11771761 = 3730^2 + 3431^2 .

It is a cyclic number.

It is not a de Polignac number, because 25684661 - 2² = 25684657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25684667) 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, 7706 + ... + 10523.

It is an arithmetic number, because the mean of its divisors is an integer number (6426075).

Almost surely, 2^25684661 is an apocalyptic number.

It is an amenable number.

25684661 is a deficient number, since it is larger than the sum of its proper divisors (19639).

25684661 is a wasteful number, since it uses less digits than its factorization.

25684661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19638.

The product of its digits is 69120, while the sum is 38.

The square root of 25684661 is about 5068.0036503539. The cubic root of 25684661 is about 295.0470517691.

The spelling of 25684661 in words is "twenty-five million, six hundred eighty-four thousand, six hundred sixty-one".