25442 has 4 divisors (see below), whose sum is σ = 38166. Its totient is φ = 12720.

The previous prime is 25439. The next prime is 25447. The reversal of 25442 is 24452.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17161 + 8281 = 131^2 + 91^2 .

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 25442.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 25442.

It is not an unprimeable number, because it can be changed into a prime (25447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6359 + ... + 6362.

2²⁵⁴⁴² is an apocalyptic number.

25442 is a deficient number, since it is larger than the sum of its proper divisors (12724).

25442 is a wasteful number, since it uses less digits than its factorization.

25442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12723.

The product of its digits is 320, while the sum is 17.

The square root of 25442 is about 159.5054857991. The cubic root of 25442 is about 29.4114938014.

Subtracting from 25442 its sum of digits (17), we obtain a triangular number (25425 = T₂₂₅).

Adding to 25442 its reverse (24452), we get a palindrome (49894).

Subtracting from 25442 its reverse (24452), we obtain a triangular number (990 = T₄₄).

The spelling of 25442 in words is "twenty-five thousand, four hundred forty-two".