6639937 has 2 divisors, whose sum is σ = 6639938. Its totient is φ = 6639936.

The previous prime is 6639929. The next prime is 6639943. The reversal of 6639937 is 7399366.

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., 6370576 + 269361 = 2524^2 + 519^2 .

It is a cyclic number.

It is not a de Polignac number, because 6639937 - 2³ = 6639929 is a prime.

It is a d-powerful number, because it can be written as 6² + 6⁸ + 3¹¹ + 9² + 9² + 3¹⁴ + 7 .

It is a junction number, because it is equal to n+sod(n) for n = 6639893 and 6639902.

It is not a weakly prime, because it can be changed into another prime (6639907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3319968 + 3319969.

It is an arithmetic number, because the mean of its divisors is an integer number (3319969).

Almost surely, 2^6639937 is an apocalyptic number.

It is an amenable number.

6639937 is a deficient number, since it is larger than the sum of its proper divisors (1).

6639937 is an equidigital number, since it uses as much as digits as its factorization.

6639937 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 43.

The square root of 6639937 is about 2576.8075209452. The cubic root of 6639937 is about 187.9553330583.

The spelling of 6639937 in words is "six million, six hundred thirty-nine thousand, nine hundred thirty-seven".