18454921 has 4 divisors (see below), whose sum is σ = 18504772. Its totient is φ = 18405072.

The previous prime is 18454883. The next prime is 18454927. The reversal of 18454921 is 12945481.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6969600 + 11485321 = 2640^2 + 3389^2 .

It is a cyclic number.

It is not a de Polignac number, because 18454921 - 2¹¹ = 18452873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18454927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24366 + ... + 25111.

It is an arithmetic number, because the mean of its divisors is an integer number (4626193).

It is a Poulet number, since it divides 2^18454920-1.

Almost surely, 2^18454921 is an apocalyptic number.

It is an amenable number.

18454921 is a deficient number, since it is larger than the sum of its proper divisors (49851).

18454921 is an equidigital number, since it uses as much as digits as its factorization.

18454921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49850.

The product of its digits is 11520, while the sum is 34.

The square root of 18454921 is about 4295.9191100392. The cubic root of 18454921 is about 264.2636303228.

The spelling of 18454921 in words is "eighteen million, four hundred fifty-four thousand, nine hundred twenty-one".