25613281 has 4 divisors (see below), whose sum is σ = 25623472. Its totient is φ = 25603092.

The previous prime is 25613227. The next prime is 25613299. The reversal of 25613281 is 18231652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 25613281 - 2¹¹ = 25611233 is a prime.

It is a super-2 number, since 2×25613281² = 1312080327169922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25613201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666 + ... + 7348.

It is an arithmetic number, because the mean of its divisors is an integer number (6405868).

Almost surely, 2^25613281 is an apocalyptic number.

It is an amenable number.

25613281 is a deficient number, since it is larger than the sum of its proper divisors (10191).

25613281 is an equidigital number, since it uses as much as digits as its factorization.

25613281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10190.

The product of its digits is 2880, while the sum is 28.

The square root of 25613281 is about 5060.9565301433. The cubic root of 25613281 is about 294.7734773535.

The spelling of 25613281 in words is "twenty-five million, six hundred thirteen thousand, two hundred eighty-one".