18428421 has 12 divisors (see below), whose sum is σ = 27008576. Its totient is φ = 11168520.

The previous prime is 18428419. The next prime is 18428437. The reversal of 18428421 is 12482481.

It is not a de Polignac number, because 18428421 - 2¹ = 18428419 is a prime.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18428441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25021 + ... + 25746.

Almost surely, 2^18428421 is an apocalyptic number.

18428421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18428421 is a deficient number, since it is larger than the sum of its proper divisors (8580155).

18428421 is a wasteful number, since it uses less digits than its factorization.

18428421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50792 (or 50781 counting only the distinct ones).

The product of its digits is 4096, while the sum is 30.

The square root of 18428421 is about 4292.8336795175. The cubic root of 18428421 is about 264.1370815861.

The spelling of 18428421 in words is "eighteen million, four hundred twenty-eight thousand, four hundred twenty-one".