439643993 has 2 divisors, whose sum is σ = 439643994. Its totient is φ = 439643992.

The previous prime is 439643977. The next prime is 439644001. The reversal of 439643993 is 399346934.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 324468169 + 115175824 = 18013^2 + 10732^2 .

It is a cyclic number.

It is not a de Polignac number, because 439643993 - 2⁴ = 439643977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (439643933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 219821996 + 219821997.

It is an arithmetic number, because the mean of its divisors is an integer number (219821997).

Almost surely, 2^439643993 is an apocalyptic number.

It is an amenable number.

439643993 is a deficient number, since it is larger than the sum of its proper divisors (1).

439643993 is an equidigital number, since it uses as much as digits as its factorization.

439643993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1889568, while the sum is 50.

The square root of 439643993 is about 20967.6892622912. The cubic root of 439643993 is about 760.3853038182.

The spelling of 439643993 in words is "four hundred thirty-nine million, six hundred forty-three thousand, nine hundred ninety-three".