25115509 has 2 divisors, whose sum is σ = 25115510. Its totient is φ = 25115508.

The previous prime is 25115459. The next prime is 25115521. The reversal of 25115509 is 90551152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23912100 + 1203409 = 4890^2 + 1097^2 .

It is a cyclic number.

It is not a de Polignac number, because 25115509 - 2⁷ = 25115381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25115539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12557754 + 12557755.

It is an arithmetic number, because the mean of its divisors is an integer number (12557755).

Almost surely, 2^25115509 is an apocalyptic number.

It is an amenable number.

25115509 is a deficient number, since it is larger than the sum of its proper divisors (1).

25115509 is an equidigital number, since it uses as much as digits as its factorization.

25115509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 25115509 is about 5011.5375884054. The cubic root of 25115509 is about 292.8514158479.

The spelling of 25115509 in words is "twenty-five million, one hundred fifteen thousand, five hundred nine".