18428921 has 8 divisors (see below), whose sum is σ = 21142080. Its totient is φ = 15735888.

The previous prime is 18428909. The next prime is 18428929. The reversal of 18428921 is 12982481.

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

It is not a de Polignac number, because 18428921 - 2⁶ = 18428857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18428929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3011 + ... + 6776.

It is an arithmetic number, because the mean of its divisors is an integer number (2642760).

Almost surely, 2^18428921 is an apocalyptic number.

It is an amenable number.

18428921 is a deficient number, since it is larger than the sum of its proper divisors (2713159).

18428921 is an equidigital number, since it uses as much as digits as its factorization.

18428921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10063.

The product of its digits is 9216, while the sum is 35.

The square root of 18428921 is about 4292.8919157137. The cubic root of 18428921 is about 264.1394704206.

The spelling of 18428921 in words is "eighteen million, four hundred twenty-eight thousand, nine hundred twenty-one".