18966381 has 12 divisors (see below), whose sum is σ = 29417472. Its totient is φ = 10837848.

The previous prime is 18966371. The next prime is 18966391. The reversal of 18966381 is 18366981.

It is an interprime number because it is at equal distance from previous prime (18966371) and next prime (18966391).

It is not a de Polignac number, because 18966381 - 2⁷ = 18966253 is a prime.

It is a super-2 number, since 2×18966381² = 719447216474322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18966341) 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 11 ways as a sum of consecutive naturals, for example, 64365 + ... + 64658.

It is an arithmetic number, because the mean of its divisors is an integer number (2451456).

Almost surely, 2^18966381 is an apocalyptic number.

It is an amenable number.

18966381 is a deficient number, since it is larger than the sum of its proper divisors (10451091).

18966381 is a wasteful number, since it uses less digits than its factorization.

18966381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129040 (or 129033 counting only the distinct ones).

The product of its digits is 62208, while the sum is 42.

The square root of 18966381 is about 4355.0408723685. The cubic root of 18966381 is about 266.6826877527.

The spelling of 18966381 in words is "eighteen million, nine hundred sixty-six thousand, three hundred eighty-one".