18420043 has 4 divisors (see below), whose sum is σ = 18917920. Its totient is φ = 17922168.

The previous prime is 18420011. The next prime is 18420047. The reversal of 18420043 is 34002481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34002481 = 263 ⋅129287.

It is a cyclic number.

It is not a de Polignac number, because 18420043 - 2⁵ = 18420011 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18419996 and 18420023.

It is not an unprimeable number, because it can be changed into a prime (18420047) 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, 248883 + ... + 248956.

It is an arithmetic number, because the mean of its divisors is an integer number (4729480).

Almost surely, 2^18420043 is an apocalyptic number.

18420043 is a deficient number, since it is larger than the sum of its proper divisors (497877).

18420043 is an equidigital number, since it uses as much as digits as its factorization.

18420043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497876.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 18420043 is about 4291.8577562636. The cubic root of 18420043 is about 264.0970478449.

The spelling of 18420043 in words is "eighteen million, four hundred twenty thousand, forty-three".