25811281 has 8 divisors (see below), whose sum is σ = 26316000. Its totient is φ = 25310208.

The previous prime is 25811273. The next prime is 25811339. The reversal of 25811281 is 18211852.

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 25811281 - 2³ = 25811273 is a prime.

It is a super-2 number, since 2×25811281² = 1332444453721922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25811231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16470 + ... + 17968.

It is an arithmetic number, because the mean of its divisors is an integer number (3289500).

Almost surely, 2^25811281 is an apocalyptic number.

It is an amenable number.

25811281 is a deficient number, since it is larger than the sum of its proper divisors (504719).

25811281 is a wasteful number, since it uses less digits than its factorization.

25811281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1823.

The product of its digits is 1280, while the sum is 28.

The square root of 25811281 is about 5080.4803906717. The cubic root of 25811281 is about 295.5310972834.

The spelling of 25811281 in words is "twenty-five million, eight hundred eleven thousand, two hundred eighty-one".