21198673 has 2 divisors, whose sum is σ = 21198674. Its totient is φ = 21198672.

The previous prime is 21198631. The next prime is 21198679. The reversal of 21198673 is 37689112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10810944 + 10387729 = 3288^2 + 3223^2 .

It is a cyclic number.

It is not a de Polignac number, because 21198673 - 2⁹ = 21198161 is a prime.

It is not a weakly prime, because it can be changed into another prime (21198679) 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, 10599336 + 10599337.

It is an arithmetic number, because the mean of its divisors is an integer number (10599337).

Almost surely, 2^21198673 is an apocalyptic number.

It is an amenable number.

21198673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21198673 is an equidigital number, since it uses as much as digits as its factorization.

21198673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 37.

The square root of 21198673 is about 4604.2016680419. The cubic root of 21198673 is about 276.7597259572.

The spelling of 21198673 in words is "twenty-one million, one hundred ninety-eight thousand, six hundred seventy-three".