18573821 has 8 divisors (see below), whose sum is σ = 21322560. Its totient is φ = 15848928.

The previous prime is 18573803. The next prime is 18573827. The reversal of 18573821 is 12837581.

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

It is a cyclic number.

It is not a de Polignac number, because 18573821 - 2⁶ = 18573757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18573827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4256 + ... + 7433.

It is an arithmetic number, because the mean of its divisors is an integer number (2665320).

Almost surely, 2^18573821 is an apocalyptic number.

It is an amenable number.

18573821 is a deficient number, since it is larger than the sum of its proper divisors (2748739).

18573821 is a wasteful number, since it uses less digits than its factorization.

18573821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11923.

The product of its digits is 13440, while the sum is 35.

The square root of 18573821 is about 4309.7356067397. The cubic root of 18573821 is about 264.8299419187.

The spelling of 18573821 in words is "eighteen million, five hundred seventy-three thousand, eight hundred twenty-one".