25209921 has 8 divisors (see below), whose sum is σ = 36669024. Its totient is φ = 15278720.

The previous prime is 25209883. The next prime is 25209931. The reversal of 25209921 is 12990252.

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 25209921 - 2¹⁴ = 25193537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25209931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 381936 + ... + 382001.

It is an arithmetic number, because the mean of its divisors is an integer number (4583628).

Almost surely, 2^25209921 is an apocalyptic number.

It is an amenable number.

25209921 is a deficient number, since it is larger than the sum of its proper divisors (11459103).

25209921 is a wasteful number, since it uses less digits than its factorization.

25209921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 763951.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 25209921 is about 5020.9482172195. The cubic root of 25209921 is about 293.2179107125.

The spelling of 25209921 in words is "twenty-five million, two hundred nine thousand, nine hundred twenty-one".