25391647 has 2 divisors, whose sum is σ = 25391648. Its totient is φ = 25391646.

The previous prime is 25391633. The next prime is 25391689. The reversal of 25391647 is 74619352.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25391647 - 2¹¹ = 25389599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25391147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12695823 + 12695824.

It is an arithmetic number, because the mean of its divisors is an integer number (12695824).

Almost surely, 2^25391647 is an apocalyptic number.

25391647 is a deficient number, since it is larger than the sum of its proper divisors (1).

25391647 is an equidigital number, since it uses as much as digits as its factorization.

25391647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 37.

The square root of 25391647 is about 5039.0125024651. The cubic root of 25391647 is about 293.9207794019.

It can be divided in two parts, 2539 and 1647, that added together give a triangular number (4186 = T₉₁).

The spelling of 25391647 in words is "twenty-five million, three hundred ninety-one thousand, six hundred forty-seven".