18683921 has 2 divisors, whose sum is σ = 18683922. Its totient is φ = 18683920.

The previous prime is 18683893. The next prime is 18683941. The reversal of 18683921 is 12938681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10010896 + 8673025 = 3164^2 + 2945^2 .

It is a cyclic number.

It is not a de Polignac number, because 18683921 - 2⁶ = 18683857 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18683941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9341960 + 9341961.

It is an arithmetic number, because the mean of its divisors is an integer number (9341961).

Almost surely, 2^18683921 is an apocalyptic number.

It is an amenable number.

18683921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18683921 is an equidigital number, since it uses as much as digits as its factorization.

18683921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 38.

The square root of 18683921 is about 4322.4901387973. The cubic root of 18683921 is about 265.3521886651.

The spelling of 18683921 in words is "eighteen million, six hundred eighty-three thousand, nine hundred twenty-one".