25810 has 16 divisors (see below), whose sum is σ = 48600. Its totient is φ = 9856.

The previous prime is 25801. The next prime is 25819. The reversal of 25810 is 1852.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (25801) and next prime (25819).

It can be written as a sum of positive squares in 4 ways, for example, as 17161 + 8649 = 131^2 + 93^2 .

It is a super-2 number, since 2×25810² = 1332312200, which contains 22 as substring.

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

It is a plaindrome in base 15.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (25819) by changing a digit.

25810 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 in 7 ways as a sum of consecutive naturals, for example, 246 + ... + 334.

2²⁵⁸¹⁰ is an apocalyptic number.

25810 is a deficient number, since it is larger than the sum of its proper divisors (22790).

25810 is a wasteful number, since it uses less digits than its factorization.

25810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 25810 is about 160.6549096667. The cubic root of 25810 is about 29.5526208186.

The spelling of 25810 in words is "twenty-five thousand, eight hundred ten".