6516649 has 2 divisors, whose sum is σ = 6516650. Its totient is φ = 6516648.

The previous prime is 6516647. The next prime is 6516667. The reversal of 6516649 is 9466156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6411024 + 105625 = 2532^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 6516649 - 2¹ = 6516647 is a prime.

Together with 6516647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (6516647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3258324 + 3258325.

It is an arithmetic number, because the mean of its divisors is an integer number (3258325).

Almost surely, 2^6516649 is an apocalyptic number.

It is an amenable number.

6516649 is a deficient number, since it is larger than the sum of its proper divisors (1).

6516649 is an equidigital number, since it uses as much as digits as its factorization.

6516649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 37.

The square root of 6516649 is about 2552.7728061855. The cubic root of 6516649 is about 186.7847619347.

The spelling of 6516649 in words is "six million, five hundred sixteen thousand, six hundred forty-nine".