25680921 has 16 divisors (see below), whose sum is σ = 40483200. Its totient is φ = 14168448.

The previous prime is 25680911. The next prime is 25680937. The reversal of 25680921 is 12908652.

It is not a de Polignac number, because 25680921 - 2¹⁰ = 25679897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25680901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20476 + ... + 21693.

It is an arithmetic number, because the mean of its divisors is an integer number (2530200).

Almost surely, 2^25680921 is an apocalyptic number.

25680921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25680921 is a deficient number, since it is larger than the sum of its proper divisors (14802279).

25680921 is a wasteful number, since it uses less digits than its factorization.

25680921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42208.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 25680921 is about 5067.6346553397. The cubic root of 25680921 is about 295.0327302572.

The spelling of 25680921 in words is "twenty-five million, six hundred eighty thousand, nine hundred twenty-one".