25566665 has 8 divisors (see below), whose sum is σ = 30876360. Its totient is φ = 20322432.

The previous prime is 25566649. The next prime is 25566677. The reversal of 25566665 is 56666552.

It can be written as a sum of positive squares in 4 ways, for example, as 6661561 + 18905104 = 2581^2 + 4348^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 25566665 - 2⁴ = 25566649 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15500 + ... + 17069.

It is an arithmetic number, because the mean of its divisors is an integer number (3859545).

Almost surely, 2^25566665 is an apocalyptic number.

It is an amenable number.

25566665 is a deficient number, since it is larger than the sum of its proper divisors (5309695).

25566665 is a wasteful number, since it uses less digits than its factorization.

25566665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32731.

The product of its digits is 324000, while the sum is 41.

The square root of 25566665 is about 5056.3489792537. The cubic root of 25566665 is about 294.5945401694.

The spelling of 25566665 in words is "twenty-five million, five hundred sixty-six thousand, six hundred sixty-five".