18866881 has 8 divisors (see below), whose sum is σ = 21020544. Its totient is φ = 16786320.

The previous prime is 18866863. The next prime is 18866891.

18866881 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18866881 is a prime.

It is a super-2 number, since 2×18866881² = 711918397336322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18866801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17730 + ... + 18763.

It is an arithmetic number, because the mean of its divisors is an integer number (2627568).

Almost surely, 2^18866881 is an apocalyptic number.

18866881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18866881 is a deficient number, since it is larger than the sum of its proper divisors (2153663).

18866881 is a wasteful number, since it uses less digits than its factorization.

18866881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36551.

The product of its digits is 147456, while the sum is 46.

The square root of 18866881 is about 4343.6023068416. The cubic root of 18866881 is about 266.2155196446.

The spelling of 18866881 in words is "eighteen million, eight hundred sixty-six thousand, eight hundred eighty-one".