6647987 has 2 divisors, whose sum is σ = 6647988. Its totient is φ = 6647986.

The previous prime is 6647983. The next prime is 6648001. The reversal of 6647987 is 7897466.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6647987 - 2² = 6647983 is a prime.

It is a d-powerful number, because it can be written as 6⁵ + 6⁶ + 4⁹ + 7⁴ + 9⁶ + 8⁵ + 7⁸ .

It is not a weakly prime, because it can be changed into another prime (6647983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3323993 + 3323994.

It is an arithmetic number, because the mean of its divisors is an integer number (3323994).

Almost surely, 2^6647987 is an apocalyptic number.

6647987 is a deficient number, since it is larger than the sum of its proper divisors (1).

6647987 is an equidigital number, since it uses as much as digits as its factorization.

6647987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 47.

The square root of 6647987 is about 2578.3690581451. The cubic root of 6647987 is about 188.0312589489.

It can be divided in two parts, 66479 and 87, that added together give a palindrome (66566).

The spelling of 6647987 in words is "six million, six hundred forty-seven thousand, nine hundred eighty-seven".