18826921 has 3 divisors (see below), whose sum is σ = 18831261. Its totient is φ = 18822582.

The previous prime is 18826901. The next prime is 18826937. The reversal of 18826921 is 12962881.

The square root of 18826921 is 4339.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12962881 = 2393 ⋅5417.

It is not a de Polignac number, because 18826921 - 2¹¹ = 18824873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18826901) 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 2 ways as a sum of consecutive naturals, for example, 2170 + ... + 6508.

It is an arithmetic number, because the mean of its divisors is an integer number (6277087).

Almost surely, 2^18826921 is an apocalyptic number.

18826921 is the 4339-th square number.

18826921 is the 2170-th centered octagonal number.

It is an amenable number.

18826921 is a deficient number, since it is larger than the sum of its proper divisors (4340).

18826921 is an frugal number, since it uses more digits than its factorization.

18826921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8678 (or 4339 counting only the distinct ones).

The product of its digits is 13824, while the sum is 37.

The cubic root of 18826921 is about 266.0274388941.

The spelling of 18826921 in words is "eighteen million, eight hundred twenty-six thousand, nine hundred twenty-one".