18850921 has 2 divisors, whose sum is σ = 18850922. Its totient is φ = 18850920.

The previous prime is 18850903. The next prime is 18850927. The reversal of 18850921 is 12905881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14356521 + 4494400 = 3789^2 + 2120^2 .

It is a cyclic number.

It is not a de Polignac number, because 18850921 - 2¹⁷ = 18719849 is a prime.

It is not a weakly prime, because it can be changed into another prime (18850927) 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 as a sum of consecutive naturals, namely, 9425460 + 9425461.

It is an arithmetic number, because the mean of its divisors is an integer number (9425461).

Almost surely, 2^18850921 is an apocalyptic number.

It is an amenable number.

18850921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18850921 is an equidigital number, since it uses as much as digits as its factorization.

18850921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 18850921 is about 4341.7647333774. The cubic root of 18850921 is about 266.1404321881.

The spelling of 18850921 in words is "eighteen million, eight hundred fifty thousand, nine hundred twenty-one".