25440647 has 2 divisors, whose sum is σ = 25440648. Its totient is φ = 25440646.

The previous prime is 25440581. The next prime is 25440659. The reversal of 25440647 is 74604452.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25440647 - 2¹⁴ = 25424263 is a prime.

It is equal to p_1591664 and since 25440647 and 1591664 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25440697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12720323 + 12720324.

It is an arithmetic number, because the mean of its divisors is an integer number (12720324).

Almost surely, 2^25440647 is an apocalyptic number.

25440647 is a deficient number, since it is larger than the sum of its proper divisors (1).

25440647 is an equidigital number, since it uses as much as digits as its factorization.

25440647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26880, while the sum is 32.

The square root of 25440647 is about 5043.8722228066. The cubic root of 25440647 is about 294.1097242658.

The spelling of 25440647 in words is "twenty-five million, four hundred forty thousand, six hundred forty-seven".