25816989 has 32 divisors (see below), whose sum is σ = 39657600. Its totient is φ = 14792960.

The previous prime is 25816981. The next prime is 25817027. The reversal of 25816989 is 98961852.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 25816989 - 2³ = 25816981 is a prime.

It is a super-2 number, since 2×25816989² = 1333033842052242, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25816981) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50467 + ... + 50975.

It is an arithmetic number, because the mean of its divisors is an integer number (1239300).

Almost surely, 2^25816989 is an apocalyptic number.

25816989 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

25816989 is a deficient number, since it is larger than the sum of its proper divisors (13840611).

25816989 is a wasteful number, since it uses less digits than its factorization.

25816989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605.

The product of its digits is 311040, while the sum is 48.

The square root of 25816989 is about 5081.0421175188. The cubic root of 25816989 is about 295.5528806162.

The spelling of 25816989 in words is "twenty-five million, eight hundred sixteen thousand, nine hundred eighty-nine".