6643513 has 2 divisors, whose sum is σ = 6643514. Its totient is φ = 6643512.

The previous prime is 6643499. The next prime is 6643537. The reversal of 6643513 is 3153466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5076009 + 1567504 = 2253^2 + 1252^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6643513 is a prime.

It is equal to p₄₅₃₉₃₄ and since 6643513 and 453934 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (6643213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3321756 + 3321757.

It is an arithmetic number, because the mean of its divisors is an integer number (3321757).

Almost surely, 2^6643513 is an apocalyptic number.

It is an amenable number.

6643513 is a deficient number, since it is larger than the sum of its proper divisors (1).

6643513 is an equidigital number, since it uses as much as digits as its factorization.

6643513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 28.

The square root of 6643513 is about 2577.5013094080. The cubic root of 6643513 is about 187.9890687020.

Adding to 6643513 its reverse (3153466), we get a palindrome (9796979).

The spelling of 6643513 in words is "six million, six hundred forty-three thousand, five hundred thirteen".