3945643673 has 2 divisors, whose sum is σ = 3945643674. Its totient is φ = 3945643672.

The previous prime is 3945643621. The next prime is 3945643711. The reversal of 3945643673 is 3763465493.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2591624464 + 1354019209 = 50908^2 + 36797^2 .

It is an emirp because it is prime and its reverse (3763465493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3945643673 - 2³⁰ = 2871901849 is a prime.

It is not a weakly prime, because it can be changed into another prime (3945643613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1972821836 + 1972821837.

It is an arithmetic number, because the mean of its divisors is an integer number (1972821837).

Almost surely, 2^3945643673 is an apocalyptic number.

It is an amenable number.

3945643673 is a deficient number, since it is larger than the sum of its proper divisors (1).

3945643673 is an equidigital number, since it uses as much as digits as its factorization.

3945643673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4898880, while the sum is 50.

The square root of 3945643673 is about 62814.3588122970. The cubic root of 3945643673 is about 1580.1777924428.

The spelling of 3945643673 in words is "three billion, nine hundred forty-five million, six hundred forty-three thousand, six hundred seventy-three".