18430421 has 4 divisors (see below), whose sum is σ = 18439392. Its totient is φ = 18421452.

The previous prime is 18430417. The next prime is 18430453. The reversal of 18430421 is 12403481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18430421 - 2² = 18430417 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 (18430481) 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 3 ways as a sum of consecutive naturals, for example, 296 + ... + 6078.

It is an arithmetic number, because the mean of its divisors is an integer number (4609848).

Almost surely, 2^18430421 is an apocalyptic number.

It is an amenable number.

18430421 is a deficient number, since it is larger than the sum of its proper divisors (8971).

18430421 is an equidigital number, since it uses as much as digits as its factorization.

18430421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8970.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 18430421 is about 4293.0666195623. The cubic root of 18430421 is about 264.1466366650.

The spelling of 18430421 in words is "eighteen million, four hundred thirty thousand, four hundred twenty-one".