25615409 has 2 divisors, whose sum is σ = 25615410. Its totient is φ = 25615408.

The previous prime is 25615351. The next prime is 25615427. The reversal of 25615409 is 90451652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23280625 + 2334784 = 4825^2 + 1528^2 .

It is a cyclic number.

It is not a de Polignac number, because 25615409 - 2¹⁶ = 25549873 is a prime.

It is a super-2 number, since 2×25615409² = 1312298356474562, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25618409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12807704 + 12807705.

It is an arithmetic number, because the mean of its divisors is an integer number (12807705).

Almost surely, 2^25615409 is an apocalyptic number.

It is an amenable number.

25615409 is a deficient number, since it is larger than the sum of its proper divisors (1).

25615409 is an equidigital number, since it uses as much as digits as its factorization.

25615409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 25615409 is about 5061.1667627139. The cubic root of 25615409 is about 294.7816405740.

The spelling of 25615409 in words is "twenty-five million, six hundred fifteen thousand, four hundred nine".