25521647 has 2 divisors, whose sum is σ = 25521648. Its totient is φ = 25521646.

The previous prime is 25521637. The next prime is 25521667. The reversal of 25521647 is 74612552.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25521647 - 2⁴ = 25521631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25521637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12760823 + 12760824.

It is an arithmetic number, because the mean of its divisors is an integer number (12760824).

Almost surely, 2^25521647 is an apocalyptic number.

25521647 is a deficient number, since it is larger than the sum of its proper divisors (1).

25521647 is an equidigital number, since it uses as much as digits as its factorization.

25521647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16800, while the sum is 32.

The square root of 25521647 is about 5051.8953868820. The cubic root of 25521647 is about 294.4215303978.

The spelling of 25521647 in words is "twenty-five million, five hundred twenty-one thousand, six hundred forty-seven".