18420443 has 4 divisors (see below), whose sum is σ = 19389960. Its totient is φ = 17450928.

The previous prime is 18420433. The next prime is 18420491. The reversal of 18420443 is 34402481.

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 18420443 - 2⁴ = 18420427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18420433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 484730 + ... + 484767.

It is an arithmetic number, because the mean of its divisors is an integer number (4847490).

Almost surely, 2^18420443 is an apocalyptic number.

18420443 is a deficient number, since it is larger than the sum of its proper divisors (969517).

18420443 is an equidigital number, since it uses as much as digits as its factorization.

18420443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 969516.

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 18420443 is about 4291.9043558775. The cubic root of 18420443 is about 264.0989594955.

The spelling of 18420443 in words is "eighteen million, four hundred twenty thousand, four hundred forty-three".