21823219 has 4 divisors (see below), whose sum is σ = 23807160. Its totient is φ = 19839280.

The previous prime is 21823211. The next prime is 21823247. The reversal of 21823219 is 91232812.

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 21823219 - 2³ = 21823211 is a prime.

It is a super-2 number, since 2×21823219² = 952505775043922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21823211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 991954 + ... + 991975.

It is an arithmetic number, because the mean of its divisors is an integer number (5951790).

Almost surely, 2^21823219 is an apocalyptic number.

21823219 is a deficient number, since it is larger than the sum of its proper divisors (1983941).

21823219 is a wasteful number, since it uses less digits than its factorization.

21823219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1983940.

The product of its digits is 1728, while the sum is 28.

The square root of 21823219 is about 4671.5328319514. The cubic root of 21823219 is about 279.4513875237.

The spelling of 21823219 in words is "twenty-one million, eight hundred twenty-three thousand, two hundred nineteen".