18187690 has 8 divisors (see below), whose sum is σ = 32737860. Its totient is φ = 7275072.

The previous prime is 18187681. The next prime is 18187717. The reversal of 18187690 is 9678181.

It can be written as a sum of positive squares in 2 ways, for example, as 15468489 + 2719201 = 3933^2 + 1649^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×18187690² = 661584135072200, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

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 3 ways as a sum of consecutive naturals, for example, 909375 + ... + 909394.

Almost surely, 2^18187690 is an apocalyptic number.

18187690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18187690 is a deficient number, since it is larger than the sum of its proper divisors (14550170).

18187690 is a wasteful number, since it uses less digits than its factorization.

18187690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1818776.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 18187690 is about 4264.7028032443. The cubic root of 18187690 is about 262.9818933401.

The spelling of 18187690 in words is "eighteen million, one hundred eighty-seven thousand, six hundred ninety".