25617989 has 4 divisors (see below), whose sum is σ = 26242860. Its totient is φ = 24993120.

The previous prime is 25617983. The next prime is 25618037. The reversal of 25617989 is 98971652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14760964 + 10857025 = 3842^2 + 3295^2 .

It is a cyclic number.

It is not a de Polignac number, because 25617989 - 2⁸ = 25617733 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25617983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312374 + ... + 312455.

It is an arithmetic number, because the mean of its divisors is an integer number (6560715).

Almost surely, 2^25617989 is an apocalyptic number.

It is an amenable number.

25617989 is a deficient number, since it is larger than the sum of its proper divisors (624871).

25617989 is an equidigital number, since it uses as much as digits as its factorization.

25617989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624870.

The product of its digits is 272160, while the sum is 47.

The square root of 25617989 is about 5061.4216382356. The cubic root of 25617989 is about 294.7915371055.

The spelling of 25617989 in words is "twenty-five million, six hundred seventeen thousand, nine hundred eighty-nine".