21230219 has 4 divisors (see below), whose sum is σ = 22153296. Its totient is φ = 20307144.

The previous prime is 21230213. The next prime is 21230227. The reversal of 21230219 is 91203212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21230219 - 2⁴ = 21230203 is a prime.

It is a super-2 number, since 2×21230219² = 901444397575922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21230219.

It is not an unprimeable number, because it can be changed into a prime (21230213) 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 in 3 ways as a sum of consecutive naturals, for example, 461504 + ... + 461549.

It is an arithmetic number, because the mean of its divisors is an integer number (5538324).

Almost surely, 2^21230219 is an apocalyptic number.

21230219 is a deficient number, since it is larger than the sum of its proper divisors (923077).

21230219 is an equidigital number, since it uses as much as digits as its factorization.

21230219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923076.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21230219 is about 4607.6261784133. The cubic root of 21230219 is about 276.8969410737.

The spelling of 21230219 in words is "twenty-one million, two hundred thirty thousand, two hundred nineteen".