25515109 has 2 divisors, whose sum is σ = 25515110. Its totient is φ = 25515108.

The previous prime is 25515107. The next prime is 25515121. The reversal of 25515109 is 90151552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22591009 + 2924100 = 4753^2 + 1710^2 .

It is a cyclic number.

It is not a de Polignac number, because 25515109 - 2¹ = 25515107 is a prime.

Together with 25515107, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25515103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12757554 + 12757555.

It is an arithmetic number, because the mean of its divisors is an integer number (12757555).

Almost surely, 2^25515109 is an apocalyptic number.

It is an amenable number.

25515109 is a deficient number, since it is larger than the sum of its proper divisors (1).

25515109 is an equidigital number, since it uses as much as digits as its factorization.

25515109 is an odious number, because the sum of its binary digits is odd.

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

The square root of 25515109 is about 5051.2482615686. The cubic root of 25515109 is about 294.3963871359.

The spelling of 25515109 in words is "twenty-five million, five hundred fifteen thousand, one hundred nine".