18389806 has 4 divisors (see below), whose sum is σ = 27584712. Its totient is φ = 9194902.

The previous prime is 18389783. The next prime is 18389807. The reversal of 18389806 is 60898381.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18389807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4597450 + ... + 4597453.

It is an arithmetic number, because the mean of its divisors is an integer number (6896178).

Almost surely, 2^18389806 is an apocalyptic number.

18389806 is a deficient number, since it is larger than the sum of its proper divisors (9194906).

18389806 is an equidigital number, since it uses as much as digits as its factorization.

18389806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9194905.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 18389806 is about 4288.3337090297. Note that the first 3 decimals coincide. The cubic root of 18389806 is about 263.9524612136.

The spelling of 18389806 in words is "eighteen million, three hundred eighty-nine thousand, eight hundred six".