6643487 has 2 divisors, whose sum is σ = 6643488. Its totient is φ = 6643486.

The previous prime is 6643453. The next prime is 6643489. The reversal of 6643487 is 7843466.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6643487 - 2⁶ = 6643423 is a prime.

Together with 6643489, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6643487.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6643489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3321743 + 3321744.

It is an arithmetic number, because the mean of its divisors is an integer number (3321744).

Almost surely, 2^6643487 is an apocalyptic number.

6643487 is a deficient number, since it is larger than the sum of its proper divisors (1).

6643487 is an equidigital number, since it uses as much as digits as its factorization.

6643487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 38.

The square root of 6643487 is about 2577.4962657587. The cubic root of 6643487 is about 187.9888234641.

The spelling of 6643487 in words is "six million, six hundred forty-three thousand, four hundred eighty-seven".