6699681 has 6 divisors (see below), whose sum is σ = 9677330. Its totient is φ = 4466448.

The previous prime is 6699643. The next prime is 6699703. The reversal of 6699681 is 1869966.

It can be written as a sum of positive squares in only one way, i.e., 6350400 + 349281 = 2520^2 + 591^2 .

It is not a de Polignac number, because 6699681 - 2⁶ = 6699617 is a prime.

It is a super-2 number, since 2×6699681² = 89771451003522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6699611) 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 in 5 ways as a sum of consecutive naturals, for example, 372196 + ... + 372213.

Almost surely, 2^6699681 is an apocalyptic number.

It is an amenable number.

6699681 is a deficient number, since it is larger than the sum of its proper divisors (2977649).

6699681 is a wasteful number, since it uses less digits than its factorization.

6699681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 744415 (or 744412 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 6699681 is about 2588.3742001496. The cubic root of 6699681 is about 188.5173711145.

The spelling of 6699681 in words is "six million, six hundred ninety-nine thousand, six hundred eighty-one".