18686669 has 4 divisors (see below), whose sum is σ = 18697344. Its totient is φ = 18675996.

The previous prime is 18686651. The next prime is 18686711. The reversal of 18686669 is 96668681.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18686669 is a prime.

It is a super-2 number, since 2×18686669² = 698383196631122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18686609) 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, 2027 + ... + 6440.

It is an arithmetic number, because the mean of its divisors is an integer number (4674336).

Almost surely, 2^18686669 is an apocalyptic number.

It is an amenable number.

18686669 is a deficient number, since it is larger than the sum of its proper divisors (10675).

18686669 is an equidigital number, since it uses as much as digits as its factorization.

18686669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10674.

The product of its digits is 746496, while the sum is 50.

The square root of 18686669 is about 4322.8079994374. The cubic root of 18686669 is about 265.3651972134.

The spelling of 18686669 in words is "eighteen million, six hundred eighty-six thousand, six hundred sixty-nine".