25585581 has 16 divisors (see below), whose sum is σ = 39063168. Its totient is φ = 14592000.

The previous prime is 25585577. The next prime is 25585583. The reversal of 25585581 is 18558552.

It is not a de Polignac number, because 25585581 - 2² = 25585577 is a prime.

It is a super-2 number, since 2×25585581² = 1309243910215122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25585583) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15181 + ... + 16781.

It is an arithmetic number, because the mean of its divisors is an integer number (2441448).

Almost surely, 2^25585581 is an apocalyptic number.

25585581 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

25585581 is a deficient number, since it is larger than the sum of its proper divisors (13477587).

25585581 is a wasteful number, since it uses less digits than its factorization.

25585581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2372.

The product of its digits is 80000, while the sum is 39.

The square root of 25585581 is about 5058.2191530221. The cubic root of 25585581 is about 294.6671761137.

The spelling of 25585581 in words is "twenty-five million, five hundred eighty-five thousand, five hundred eighty-one".