25830781 has 4 divisors (see below), whose sum is σ = 26664064. Its totient is φ = 24997500.

The previous prime is 25830757. The next prime is 25830821. The reversal of 25830781 is 18703852.

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.

It is a cyclic number.

It is not a de Polignac number, because 25830781 - 2⁷ = 25830653 is a prime.

It is a super-2 number, since 2×25830781² = 1334458494139922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25830751) 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, 416595 + ... + 416656.

It is an arithmetic number, because the mean of its divisors is an integer number (6666016).

Almost surely, 2^25830781 is an apocalyptic number.

It is an amenable number.

25830781 is a deficient number, since it is larger than the sum of its proper divisors (833283).

25830781 is an equidigital number, since it uses as much as digits as its factorization.

25830781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833282.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 25830781 is about 5082.3991382024. The cubic root of 25830781 is about 295.6055015172.

The spelling of 25830781 in words is "twenty-five million, eight hundred thirty thousand, seven hundred eighty-one".