25666665 has 16 divisors (see below), whose sum is σ = 41741376. Its totient is φ = 13464000.

The previous prime is 25666661. The next prime is 25666679. The reversal of 25666665 is 56666652.

25666665 is nontrivially palindromic in base 14.

It is not a de Polignac number, because 25666665 - 2² = 25666661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25666661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13111 + ... + 14940.

It is an arithmetic number, because the mean of its divisors is an integer number (2608836).

Almost surely, 2^25666665 is an apocalyptic number.

It is an amenable number.

25666665 is a deficient number, since it is larger than the sum of its proper divisors (16074711).

25666665 is a wasteful number, since it uses less digits than its factorization.

25666665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28120.

The product of its digits is 388800, while the sum is 42.

The square root of 25666665 is about 5066.2278867023. The cubic root of 25666665 is about 294.9781272685.

The spelling of 25666665 in words is "twenty-five million, six hundred sixty-six thousand, six hundred sixty-five".