18420023 has 4 divisors (see below), whose sum is σ = 18502848. Its totient is φ = 18337200.

The previous prime is 18420011. The next prime is 18420047. The reversal of 18420023 is 32002481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32002481 = 7 ⋅4571783.

It is a cyclic number.

It is not a de Polignac number, because 18420023 - 2⁴ = 18420007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18419977 and 18420004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18420053) 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, 41078 + ... + 41523.

It is an arithmetic number, because the mean of its divisors is an integer number (4625712).

Almost surely, 2^18420023 is an apocalyptic number.

18420023 is a deficient number, since it is larger than the sum of its proper divisors (82825).

18420023 is an equidigital number, since it uses as much as digits as its factorization.

18420023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82824.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 18420023 is about 4291.8554262696. The cubic root of 18420023 is about 264.0969522617.

The spelling of 18420023 in words is "eighteen million, four hundred twenty thousand, twenty-three".