6439949 has 2 divisors, whose sum is σ = 6439950. Its totient is φ = 6439948.

The previous prime is 6439933. The next prime is 6439969. The reversal of 6439949 is 9499346.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3822025 + 2617924 = 1955^2 + 1618^2 .

It is a cyclic number.

It is not a de Polignac number, because 6439949 - 2⁴ = 6439933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6439919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3219974 + 3219975.

It is an arithmetic number, because the mean of its divisors is an integer number (3219975).

Almost surely, 2^6439949 is an apocalyptic number.

It is an amenable number.

6439949 is a deficient number, since it is larger than the sum of its proper divisors (1).

6439949 is an equidigital number, since it uses as much as digits as its factorization.

6439949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 44.

The square root of 6439949 is about 2537.7054596623. The cubic root of 6439949 is about 186.0490582431.

The spelling of 6439949 in words is "six million, four hundred thirty-nine thousand, nine hundred forty-nine".