18986690 has 16 divisors (see below), whose sum is σ = 35010360. Its totient is φ = 7409280.

The previous prime is 18986689. The next prime is 18986699. The reversal of 18986690 is 9668981.

It can be written as a sum of positive squares in 4 ways, for example, as 13402921 + 5583769 = 3661^2 + 2363^2 .

It is a super-2 number, since 2×18986690² = 720988794312200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18986699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22745 + ... + 23564.

Almost surely, 2^18986690 is an apocalyptic number.

18986690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18986690 is a deficient number, since it is larger than the sum of its proper divisors (16023670).

18986690 is a wasteful number, since it uses less digits than its factorization.

18986690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46357.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 18986690 is about 4357.3719143539. The cubic root of 18986690 is about 266.7778407975. Note that the first 3 decimals are identical.

The spelling of 18986690 in words is "eighteen million, nine hundred eighty-six thousand, six hundred ninety".