2018806921 has 2 divisors, whose sum is σ = 2018806922. Its totient is φ = 2018806920.

The previous prime is 2018806877. The next prime is 2018806963. The reversal of 2018806921 is 1296088102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1277061696 + 741745225 = 35736^2 + 27235^2 .

It is a cyclic number.

It is not a de Polignac number, because 2018806921 - 2⁹ = 2018806409 is a prime.

It is not a weakly prime, because it can be changed into another prime (2018806121) 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, 1009403460 + 1009403461.

It is an arithmetic number, because the mean of its divisors is an integer number (1009403461).

Almost surely, 2^2018806921 is an apocalyptic number.

It is an amenable number.

2018806921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2018806921 is an equidigital number, since it uses as much as digits as its factorization.

2018806921 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2018806921 is about 44931.1353183959. The cubic root of 2018806921 is about 1263.8579413685.

The spelling of 2018806921 in words is "two billion, eighteen million, eight hundred six thousand, nine hundred twenty-one".