25640189 has 2 divisors, whose sum is σ = 25640190. Its totient is φ = 25640188.

The previous prime is 25640183. The next prime is 25640201. The reversal of 25640189 is 98104652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15077689 + 10562500 = 3883^2 + 3250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25640189 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25640183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12820094 + 12820095.

It is an arithmetic number, because the mean of its divisors is an integer number (12820095).

Almost surely, 2^25640189 is an apocalyptic number.

It is an amenable number.

25640189 is a deficient number, since it is larger than the sum of its proper divisors (1).

25640189 is an equidigital number, since it uses as much as digits as its factorization.

25640189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 25640189 is about 5063.6142230624. The cubic root of 25640189 is about 294.8766658618.

The spelling of 25640189 in words is "twenty-five million, six hundred forty thousand, one hundred eighty-nine".