25128399 has 16 divisors (see below), whose sum is σ = 34150400. Its totient is φ = 16432416.

The previous prime is 25128377. The next prime is 25128421. The reversal of 25128399 is 99382152.

It is an interprime number because it is at equal distance from previous prime (25128377) and next prime (25128421).

It is not a de Polignac number, because 25128399 - 2¹¹ = 25126351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25128319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54042 + ... + 54504.

It is an arithmetic number, because the mean of its divisors is an integer number (2134400).

Almost surely, 2^25128399 is an apocalyptic number.

25128399 is a deficient number, since it is larger than the sum of its proper divisors (9022001).

25128399 is a wasteful number, since it uses less digits than its factorization.

25128399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774.

The product of its digits is 38880, while the sum is 39.

The square root of 25128399 is about 5012.8234558979. The cubic root of 25128399 is about 292.9015071964.

The spelling of 25128399 in words is "twenty-five million, one hundred twenty-eight thousand, three hundred ninety-nine".