19981873 has 2 divisors, whose sum is σ = 19981874. Its totient is φ = 19981872.

The previous prime is 19981867. The next prime is 19981889. The reversal of 19981873 is 37818991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19918369 + 63504 = 4463^2 + 252^2 .

It is a cyclic number.

It is not a de Polignac number, because 19981873 - 2⁹ = 19981361 is a prime.

It is not a weakly prime, because it can be changed into another prime (19981373) 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 as a sum of consecutive naturals, namely, 9990936 + 9990937.

It is an arithmetic number, because the mean of its divisors is an integer number (9990937).

Almost surely, 2^19981873 is an apocalyptic number.

It is an amenable number.

19981873 is a deficient number, since it is larger than the sum of its proper divisors (1).

19981873 is an equidigital number, since it uses as much as digits as its factorization.

19981873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 46.

The square root of 19981873 is about 4470.1088353641. The cubic root of 19981873 is about 271.3597297911.

The spelling of 19981873 in words is "nineteen million, nine hundred eighty-one thousand, eight hundred seventy-three".