25666491 has 16 divisors (see below), whose sum is σ = 34829984. Its totient is φ = 16809984.

The previous prime is 25666477. The next prime is 25666577. The reversal of 25666491 is 19466652.

It is not a de Polignac number, because 25666491 - 2¹³ = 25658299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25666391) 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, 55935 + ... + 56391.

It is an arithmetic number, because the mean of its divisors is an integer number (2176874).

Almost surely, 2^25666491 is an apocalyptic number.

25666491 is a deficient number, since it is larger than the sum of its proper divisors (9163493).

25666491 is a wasteful number, since it uses less digits than its factorization.

25666491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750.

The product of its digits is 77760, while the sum is 39.

The square root of 25666491 is about 5066.2107141334. The cubic root of 25666491 is about 294.9774606930.

The spelling of 25666491 in words is "twenty-five million, six hundred sixty-six thousand, four hundred ninety-one".