18445649 has 2 divisors, whose sum is σ = 18445650. Its totient is φ = 18445648.

The previous prime is 18445619. The next prime is 18445673. The reversal of 18445649 is 94654481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11343424 + 7102225 = 3368^2 + 2665^2 .

It is a cyclic number.

It is not a de Polignac number, because 18445649 - 2⁸ = 18445393 is a prime.

It is not a weakly prime, because it can be changed into another prime (18445619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9222824 + 9222825.

It is an arithmetic number, because the mean of its divisors is an integer number (9222825).

Almost surely, 2^18445649 is an apocalyptic number.

It is an amenable number.

18445649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18445649 is an equidigital number, since it uses as much as digits as its factorization.

18445649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 138240, while the sum is 41.

The square root of 18445649 is about 4294.8398107496. The cubic root of 18445649 is about 264.2193663775.

The spelling of 18445649 in words is "eighteen million, four hundred forty-five thousand, six hundred forty-nine".