18966981 has 16 divisors (see below), whose sum is σ = 27846720. Its totient is φ = 11387520.

The previous prime is 18966979. The next prime is 18966989.

18966981 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18966981 - 2¹ = 18966979 is a prime.

It is a super-2 number, since 2×18966981² = 719492736508722, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18966981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18966989) 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 15 ways as a sum of consecutive naturals, for example, 961 + ... + 6233.

It is an arithmetic number, because the mean of its divisors is an integer number (1740420).

Almost surely, 2^18966981 is an apocalyptic number.

18966981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18966981 is a deficient number, since it is larger than the sum of its proper divisors (8879739).

18966981 is a wasteful number, since it uses less digits than its factorization.

18966981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5396.

The product of its digits is 186624, while the sum is 48.

The square root of 18966981 is about 4355.1097575147. The cubic root of 18966981 is about 266.6854998852.

The spelling of 18966981 in words is "eighteen million, nine hundred sixty-six thousand, nine hundred eighty-one".