4066643621 has 2 divisors, whose sum is σ = 4066643622. Its totient is φ = 4066643620.

The previous prime is 4066643597. The next prime is 4066643653. The reversal of 4066643621 is 1263466604.

It is a happy number.

4066643621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3958171396 + 108472225 = 62914^2 + 10415^2 .

It is a cyclic number.

It is not a de Polignac number, because 4066643621 - 2¹⁰ = 4066642597 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4066643821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2033321810 + 2033321811.

It is an arithmetic number, because the mean of its divisors is an integer number (2033321811).

Almost surely, 2^4066643621 is an apocalyptic number.

It is an amenable number.

4066643621 is a deficient number, since it is larger than the sum of its proper divisors (1).

4066643621 is an equidigital number, since it uses as much as digits as its factorization.

4066643621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 38.

The square root of 4066643621 is about 63770.2408729966. The cubic root of 4066643621 is about 1596.1683863528.

The spelling of 4066643621 in words is "four billion, sixty-six million, six hundred forty-three thousand, six hundred twenty-one".