43664689 has 2 divisors, whose sum is σ = 43664690. Its totient is φ = 43664688.

The previous prime is 43664671. The next prime is 43664693. The reversal of 43664689 is 98646634.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31449664 + 12215025 = 5608^2 + 3495^2 .

It is a cyclic number.

It is not a de Polignac number, because 43664689 - 2⁷ = 43664561 is a prime.

It is not a weakly prime, because it can be changed into another prime (43664609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21832344 + 21832345.

It is an arithmetic number, because the mean of its divisors is an integer number (21832345).

Almost surely, 2^43664689 is an apocalyptic number.

It is an amenable number.

43664689 is a deficient number, since it is larger than the sum of its proper divisors (1).

43664689 is an equidigital number, since it uses as much as digits as its factorization.

43664689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 46.

The square root of 43664689 is about 6607.9262253751. The cubic root of 43664689 is about 352.1357543910.

The spelling of 43664689 in words is "forty-three million, six hundred sixty-four thousand, six hundred eighty-nine".