18686690 has 32 divisors (see below), whose sum is σ = 38629440. Its totient is φ = 6436800.

The previous prime is 18686651. The next prime is 18686711. The reversal of 18686690 is 9668681.

It is a super-2 number, since 2×18686690² = 698384766312200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 2381 + ... + 6560.

It is an arithmetic number, because the mean of its divisors is an integer number (1207170).

Almost surely, 2^18686690 is an apocalyptic number.

18686690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18686690 is an abundant number, since it is smaller than the sum of its proper divisors (19942750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18686690 is a wasteful number, since it uses less digits than its factorization.

18686690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8978.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 18686690 is about 4322.8104284134. The cubic root of 18686690 is about 265.3652966188.

Subtracting from 18686690 its reverse (9668681), we obtain a square (9018009 = 3003²).

It can be divided in two parts, 1868 and 6690, that added together give a palindrome (8558).

The spelling of 18686690 in words is "eighteen million, six hundred eighty-six thousand, six hundred ninety".