18423021 has 8 divisors (see below), whose sum is σ = 25356544. Its totient is φ = 11885760.

The previous prime is 18423007. The next prime is 18423029. The reversal of 18423021 is 12032481.

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

It is not a de Polignac number, because 18423021 - 2⁷ = 18422893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18423029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98956 + ... + 99141.

It is an arithmetic number, because the mean of its divisors is an integer number (3169568).

Almost surely, 2^18423021 is an apocalyptic number.

It is an amenable number.

18423021 is a deficient number, since it is larger than the sum of its proper divisors (6933523).

18423021 is a wasteful number, since it uses less digits than its factorization.

18423021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198131.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 18423021 is about 4292.2046782510. The cubic root of 18423021 is about 264.1112794192. Note that the first 3 decimals are identical.

The spelling of 18423021 in words is "eighteen million, four hundred twenty-three thousand, twenty-one".