25724665 has 4 divisors (see below), whose sum is σ = 30869604. Its totient is φ = 20579728.

The previous prime is 25724641. The next prime is 25724683. The reversal of 25724665 is 56642752.

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 8185321 + 17539344 = 2861^2 + 4188^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25724665 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2572462 + ... + 2572471.

It is an arithmetic number, because the mean of its divisors is an integer number (7717401).

Almost surely, 2^25724665 is an apocalyptic number.

It is an amenable number.

25724665 is a deficient number, since it is larger than the sum of its proper divisors (5144939).

25724665 is an equidigital number, since it uses as much as digits as its factorization.

25724665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5144938.

The product of its digits is 100800, while the sum is 37.

The square root of 25724665 is about 5071.9488364927. The cubic root of 25724665 is about 295.2001514444.

The spelling of 25724665 in words is "twenty-five million, seven hundred twenty-four thousand, six hundred sixty-five".