6642439 has 2 divisors, whose sum is σ = 6642440. Its totient is φ = 6642438.

The previous prime is 6642431. The next prime is 6642487. The reversal of 6642439 is 9342466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6642439 - 2³ = 6642431 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6642431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3321219 + 3321220.

It is an arithmetic number, because the mean of its divisors is an integer number (3321220).

Almost surely, 2^6642439 is an apocalyptic number.

6642439 is a deficient number, since it is larger than the sum of its proper divisors (1).

6642439 is an equidigital number, since it uses as much as digits as its factorization.

6642439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 34.

The square root of 6642439 is about 2577.2929596769. The cubic root of 6642439 is about 187.9789379604.

The spelling of 6642439 in words is "six million, six hundred forty-two thousand, four hundred thirty-nine".