25647121 has 2 divisors, whose sum is σ = 25647122. Its totient is φ = 25647120.

The previous prime is 25647119. The next prime is 25647161. The reversal of 25647121 is 12174652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25644096 + 3025 = 5064^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 25647121 - 2¹ = 25647119 is a prime.

Together with 25647119, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 25647121.

It is not a weakly prime, because it can be changed into another prime (25647161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12823560 + 12823561.

It is an arithmetic number, because the mean of its divisors is an integer number (12823561).

Almost surely, 2^25647121 is an apocalyptic number.

It is an amenable number.

25647121 is a deficient number, since it is larger than the sum of its proper divisors (1).

25647121 is an equidigital number, since it uses as much as digits as its factorization.

25647121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 28.

The square root of 25647121 is about 5064.2986681277. The cubic root of 25647121 is about 294.9032374400.

The spelling of 25647121 in words is "twenty-five million, six hundred forty-seven thousand, one hundred twenty-one".