20021231219 has 4 divisors (see below), whose sum is σ = 21841343160. Its totient is φ = 18201119280.

The previous prime is 20021231203. The next prime is 20021231231. The reversal of 20021231219 is 91213212002.

It is a happy number.

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 20021231219 - 2⁴ = 20021231203 is a prime.

It is a super-2 number, since 2×20021231219² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021231194 and 20021231203.

It is not an unprimeable number, because it can be changed into a prime (20021231519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 910055954 + ... + 910055975.

It is an arithmetic number, because the mean of its divisors is an integer number (5460335790).

Almost surely, 2^20021231219 is an apocalyptic number.

20021231219 is a deficient number, since it is larger than the sum of its proper divisors (1820111941).

20021231219 is a wasteful number, since it uses less digits than its factorization.

20021231219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1820111940.

The product of its (nonzero) digits is 432, while the sum is 23.

The spelling of 20021231219 in words is "twenty billion, twenty-one million, two hundred thirty-one thousand, two hundred nineteen".