21221323219 has 4 divisors (see below), whose sum is σ = 21477001896. Its totient is φ = 20965644544.

The previous prime is 21221323217. The next prime is 21221323237. The reversal of 21221323219 is 91232312212.

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 21221323219 - 2¹ = 21221323217 is a prime.

It is a super-2 number, since 2×21221323219² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221323217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127839214 + ... + 127839379.

It is an arithmetic number, because the mean of its divisors is an integer number (5369250474).

Almost surely, 2^21221323219 is an apocalyptic number.

21221323219 is a deficient number, since it is larger than the sum of its proper divisors (255678677).

21221323219 is an equidigital number, since it uses as much as digits as its factorization.

21221323219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255678676.

The product of its digits is 2592, while the sum is 28.

The spelling of 21221323219 in words is "twenty-one billion, two hundred twenty-one million, three hundred twenty-three thousand, two hundred nineteen".