18814921 has 4 divisors (see below), whose sum is σ = 19805200. Its totient is φ = 17824644.

The previous prime is 18814909. The next prime is 18814967. The reversal of 18814921 is 12941881.

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.

It is a cyclic number.

It is not a de Polignac number, because 18814921 - 2²³ = 10426313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18812921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 495111 + ... + 495148.

It is an arithmetic number, because the mean of its divisors is an integer number (4951300).

Almost surely, 2^18814921 is an apocalyptic number.

It is an amenable number.

18814921 is a deficient number, since it is larger than the sum of its proper divisors (990279).

18814921 is an equidigital number, since it uses as much as digits as its factorization.

18814921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990278.

The product of its digits is 4608, while the sum is 34.

The square root of 18814921 is about 4337.6169724862. The cubic root of 18814921 is about 265.9709062344.

The spelling of 18814921 in words is "eighteen million, eight hundred fourteen thousand, nine hundred twenty-one".