18686806 has 4 divisors (see below), whose sum is σ = 28030212. Its totient is φ = 9343402.

The previous prime is 18686797. The next prime is 18686807. The reversal of 18686806 is 60868681.

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: 60868681 = 1117 ⋅54493.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18686807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4671700 + ... + 4671703.

It is an arithmetic number, because the mean of its divisors is an integer number (7007553).

Almost surely, 2^18686806 is an apocalyptic number.

18686806 is a deficient number, since it is larger than the sum of its proper divisors (9343406).

18686806 is an equidigital number, since it uses as much as digits as its factorization.

18686806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9343405.

The product of its (nonzero) digits is 110592, while the sum is 43.

The square root of 18686806 is about 4322.8238455898. The cubic root of 18686806 is about 265.3658457139.

The spelling of 18686806 in words is "eighteen million, six hundred eighty-six thousand, eight hundred six".