18666698 has 4 divisors (see below), whose sum is σ = 28000050. Its totient is φ = 9333348.

The previous prime is 18666677. The next prime is 18666707. The reversal of 18666698 is 89666681.

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

It can be written as a sum of positive squares in only one way, i.e., 9443329 + 9223369 = 3073^2 + 3037^2 .

It is a super-2 number, since 2×18666698² = 696891228446408, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4666673 + ... + 4666676.

Almost surely, 2^18666698 is an apocalyptic number.

18666698 is a deficient number, since it is larger than the sum of its proper divisors (9333352).

18666698 is an equidigital number, since it uses as much as digits as its factorization.

18666698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9333351.

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

The square root of 18666698 is about 4320.4974250658. The cubic root of 18666698 is about 265.2706289515.

The spelling of 18666698 in words is "eighteen million, six hundred sixty-six thousand, six hundred ninety-eight".