6697681 has 2 divisors, whose sum is σ = 6697682. Its totient is φ = 6697680.

The previous prime is 6697667. The next prime is 6697693. The reversal of 6697681 is 1867966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5452225 + 1245456 = 2335^2 + 1116^2 .

It is a cyclic number.

It is not a de Polignac number, because 6697681 - 2⁷ = 6697553 is a prime.

It is a super-2 number, since 2×6697681² = 89717861555522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6697651) 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, 3348840 + 3348841.

It is an arithmetic number, because the mean of its divisors is an integer number (3348841).

Almost surely, 2^6697681 is an apocalyptic number.

It is an amenable number.

6697681 is a deficient number, since it is larger than the sum of its proper divisors (1).

6697681 is an equidigital number, since it uses as much as digits as its factorization.

6697681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 6697681 is about 2587.9878284103. The cubic root of 6697681 is about 188.4986104071.

The spelling of 6697681 in words is "six million, six hundred ninety-seven thousand, six hundred eighty-one".