6639497 has 2 divisors, whose sum is σ = 6639498. Its totient is φ = 6639496.

The previous prime is 6639481. The next prime is 6639509. The reversal of 6639497 is 7949366.

6639497 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6635776 + 3721 = 2576^2 + 61^2 .

It is a cyclic number.

It is not a de Polignac number, because 6639497 - 2⁴ = 6639481 is a prime.

It is not a weakly prime, because it can be changed into another prime (6639407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3319748 + 3319749.

It is an arithmetic number, because the mean of its divisors is an integer number (3319749).

Almost surely, 2^6639497 is an apocalyptic number.

It is an amenable number.

6639497 is a deficient number, since it is larger than the sum of its proper divisors (1).

6639497 is an equidigital number, since it uses as much as digits as its factorization.

6639497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 44.

The square root of 6639497 is about 2576.7221425680. The cubic root of 6639497 is about 187.9511813033.

The spelling of 6639497 in words is "six million, six hundred thirty-nine thousand, four hundred ninety-seven".