6687997 has 4 divisors (see below), whose sum is σ = 6698140. Its totient is φ = 6677856.

The previous prime is 6687983. The next prime is 6688001. The reversal of 6687997 is 7997866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2643876 + 4044121 = 1626^2 + 2011^2 .

It is a cyclic number.

It is not a de Polignac number, because 6687997 - 2⁷ = 6687869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6687097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4008 + ... + 5425.

It is an arithmetic number, because the mean of its divisors is an integer number (1674535).

Almost surely, 2^6687997 is an apocalyptic number.

It is an amenable number.

6687997 is a deficient number, since it is larger than the sum of its proper divisors (10143).

6687997 is an equidigital number, since it uses as much as digits as its factorization.

6687997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10142.

The product of its digits is 1143072, while the sum is 52.

The square root of 6687997 is about 2586.1162000189. The cubic root of 6687997 is about 188.4077181999.

The spelling of 6687997 in words is "six million, six hundred eighty-seven thousand, nine hundred ninety-seven".