21213319 has 4 divisors (see below), whose sum is σ = 21706696. Its totient is φ = 20719944.

The previous prime is 21213293. The next prime is 21213341. The reversal of 21213319 is 91331212.

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 21213319 - 2⁵ = 21213287 is a prime.

It is a super-2 number, since 2×21213319² = 900009805991522, 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 21213319.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213349) 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 in 3 ways as a sum of consecutive naturals, for example, 246624 + ... + 246709.

It is an arithmetic number, because the mean of its divisors is an integer number (5426674).

Almost surely, 2^21213319 is an apocalyptic number.

21213319 is a deficient number, since it is larger than the sum of its proper divisors (493377).

21213319 is an equidigital number, since it uses as much as digits as its factorization.

21213319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493376.

The product of its digits is 324, while the sum is 22.

The square root of 21213319 is about 4605.7918971660. The cubic root of 21213319 is about 276.8234483391.

It can be divided in two parts, 212 and 13319, that added together give a palindrome (13531).

The spelling of 21213319 in words is "twenty-one million, two hundred thirteen thousand, three hundred nineteen".