21199019 has 2 divisors, whose sum is σ = 21199020. Its totient is φ = 21199018.

The previous prime is 21198997. The next prime is 21199027. The reversal of 21199019 is 91099112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21199019 - 2²⁰ = 20150443 is a prime.

It is a super-2 number, since 2×21199019² = 898796813124722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21199069) 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, 10599509 + 10599510.

It is an arithmetic number, because the mean of its divisors is an integer number (10599510).

Almost surely, 2^21199019 is an apocalyptic number.

21199019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21199019 is an equidigital number, since it uses as much as digits as its factorization.

21199019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 32.

The square root of 21199019 is about 4604.2392422636. The cubic root of 21199019 is about 276.7612316857.

The spelling of 21199019 in words is "twenty-one million, one hundred ninety-nine thousand, nineteen".