6691018 has 4 divisors (see below), whose sum is σ = 10036530. Its totient is φ = 3345508.

The previous prime is 6691007. The next prime is 6691019. The reversal of 6691018 is 8101966.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8101966 = 2 ⋅4050983.

It can be written as a sum of positive squares in only one way, i.e., 3790809 + 2900209 = 1947^2 + 1703^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (6691019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1672753 + ... + 1672756.

Almost surely, 2^6691018 is an apocalyptic number.

6691018 is a deficient number, since it is larger than the sum of its proper divisors (3345512).

6691018 is a wasteful number, since it uses less digits than its factorization.

6691018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3345511.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 6691018 is about 2586.7002145591. The cubic root of 6691018 is about 188.4360821499.

The spelling of 6691018 in words is "six million, six hundred ninety-one thousand, eighteen".