25128989 has 2 divisors, whose sum is σ = 25128990. Its totient is φ = 25128988.

The previous prime is 25128977. The next prime is 25129007. The reversal of 25128989 is 98982152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16337764 + 8791225 = 4042^2 + 2965^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25128989 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 (25128919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12564494 + 12564495.

It is an arithmetic number, because the mean of its divisors is an integer number (12564495).

Almost surely, 2^25128989 is an apocalyptic number.

It is an amenable number.

25128989 is a deficient number, since it is larger than the sum of its proper divisors (1).

25128989 is an equidigital number, since it uses as much as digits as its factorization.

25128989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 44.

The square root of 25128989 is about 5012.8823046228. The cubic root of 25128989 is about 292.9037995634.

The spelling of 25128989 in words is "twenty-five million, one hundred twenty-eight thousand, nine hundred eighty-nine".