6691986123 has 4 divisors (see below), whose sum is σ = 8922648168. Its totient is φ = 4461324080.

The previous prime is 6691986121. The next prime is 6691986127. The reversal of 6691986123 is 3216891966.

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

It is a cyclic number.

It is not a de Polignac number, because 6691986123 - 2¹ = 6691986121 is a prime.

It is a super-2 number, since 2×6691986123² = 89565356540849142258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6691986121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1115331018 + ... + 1115331023.

It is an arithmetic number, because the mean of its divisors is an integer number (2230662042).

Almost surely, 2^6691986123 is an apocalyptic number.

6691986123 is a deficient number, since it is larger than the sum of its proper divisors (2230662045).

6691986123 is a wasteful number, since it uses less digits than its factorization.

6691986123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2230662044.

The product of its digits is 839808, while the sum is 51.

The square root of 6691986123 is about 81804.5605269046. The cubic root of 6691986123 is about 1884.4516998018.

The spelling of 6691986123 in words is "six billion, six hundred ninety-one million, nine hundred eighty-six thousand, one hundred twenty-three".