25680491 has 4 divisors (see below), whose sum is σ = 25708392. Its totient is φ = 25652592.

The previous prime is 25680481. The next prime is 25680521. The reversal of 25680491 is 19408652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25680491 - 2⁶ = 25680427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25680401) 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, 12521 + ... + 14426.

It is an arithmetic number, because the mean of its divisors is an integer number (6427098).

Almost surely, 2^25680491 is an apocalyptic number.

25680491 is a deficient number, since it is larger than the sum of its proper divisors (27901).

25680491 is an equidigital number, since it uses as much as digits as its factorization.

25680491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27900.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 25680491 is about 5067.5922290571. The cubic root of 25680491 is about 295.0310835771.

The spelling of 25680491 in words is "twenty-five million, six hundred eighty thousand, four hundred ninety-one".