6499681 has 2 divisors, whose sum is σ = 6499682. Its totient is φ = 6499680.

The previous prime is 6499673. The next prime is 6499699. The reversal of 6499681 is 1869946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6150400 + 349281 = 2480^2 + 591^2 .

It is a cyclic number.

It is not a de Polignac number, because 6499681 - 2³ = 6499673 is a prime.

It is a super-2 number, since 2×6499681² = 84491706203522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6499601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3249840 + 3249841.

It is an arithmetic number, because the mean of its divisors is an integer number (3249841).

Almost surely, 2^6499681 is an apocalyptic number.

It is an amenable number.

6499681 is a deficient number, since it is larger than the sum of its proper divisors (1).

6499681 is an equidigital number, since it uses as much as digits as its factorization.

6499681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 43.

The square root of 6499681 is about 2549.4471949817. The cubic root of 6499681 is about 186.6225047882.

The spelling of 6499681 in words is "six million, four hundred ninety-nine thousand, six hundred eighty-one".