6443639 has 2 divisors, whose sum is σ = 6443640. Its totient is φ = 6443638.

The previous prime is 6443621. The next prime is 6443677. The reversal of 6443639 is 9363446.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6443639 - 2⁸ = 6443383 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 6443599 and 6443608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6443839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3221819 + 3221820.

It is an arithmetic number, because the mean of its divisors is an integer number (3221820).

Almost surely, 2^6443639 is an apocalyptic number.

6443639 is a deficient number, since it is larger than the sum of its proper divisors (1).

6443639 is an equidigital number, since it uses as much as digits as its factorization.

6443639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 35.

The square root of 6443639 is about 2538.4323902755. The cubic root of 6443639 is about 186.0845859543.

The spelling of 6443639 in words is "six million, four hundred forty-three thousand, six hundred thirty-nine".