25399 has 4 divisors (see below), whose sum is σ = 27720. Its totient is φ = 23080.

The previous prime is 25391. The next prime is 25409. The reversal of 25399 is 99352.

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 25399 - 2³ = 25391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25391) 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, 1144 + ... + 1165.

It is an arithmetic number, because the mean of its divisors is an integer number (6930).

2²⁵³⁹⁹ is an apocalyptic number.

25399 is a deficient number, since it is larger than the sum of its proper divisors (2321).

25399 is a wasteful number, since it uses less digits than its factorization.

25399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2320.

The product of its digits is 2430, while the sum is 28.

The square root of 25399 is about 159.3706371952. The cubic root of 25399 is about 29.3949148192.

It can be divided in two parts, 25 and 399, that added together give a palindrome (424).

The spelling of 25399 in words is "twenty-five thousand, three hundred ninety-nine".