18966919 has 4 divisors (see below), whose sum is σ = 19002520. Its totient is φ = 18931320.

The previous prime is 18966901. The next prime is 18966931. The reversal of 18966919 is 91966981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18966919 - 2¹⁹ = 18442631 is a prime.

It is a super-2 number, since 2×18966919² = 719488032705122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18966949) 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 3 ways as a sum of consecutive naturals, for example, 16989 + ... + 18070.

It is an arithmetic number, because the mean of its divisors is an integer number (4750630).

Almost surely, 2^18966919 is an apocalyptic number.

18966919 is a deficient number, since it is larger than the sum of its proper divisors (35601).

18966919 is an equidigital number, since it uses as much as digits as its factorization.

18966919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35600.

The product of its digits is 209952, while the sum is 49.

The square root of 18966919 is about 4355.1026394334. The cubic root of 18966919 is about 266.6852093009.

The spelling of 18966919 in words is "eighteen million, nine hundred sixty-six thousand, nine hundred nineteen".