25439921 has 8 divisors (see below), whose sum is σ = 27436584. Its totient is φ = 23448960.

The previous prime is 25439903. The next prime is 25439927. The reversal of 25439921 is 12993452.

It can be written as a sum of positive squares in 4 ways, for example, as 3010225 + 22429696 = 1735^2 + 4736^2 .

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 25439921 - 2¹⁴ = 25423537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25439927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14525 + ... + 16181.

It is an arithmetic number, because the mean of its divisors is an integer number (3429573).

Almost surely, 2^25439921 is an apocalyptic number.

It is an amenable number.

25439921 is a deficient number, since it is larger than the sum of its proper divisors (1996663).

25439921 is a wasteful number, since it uses less digits than its factorization.

25439921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2851.

The product of its digits is 19440, while the sum is 35.

The square root of 25439921 is about 5043.8002537769. The cubic root of 25439921 is about 294.1069265685.

The spelling of 25439921 in words is "twenty-five million, four hundred thirty-nine thousand, nine hundred twenty-one".