20213111221 has 16 divisors (see below), whose sum is σ = 21688300800. Its totient is φ = 18779387328.

The previous prime is 20213111213. The next prime is 20213111239. The reversal of 20213111221 is 12211131202.

It is a cyclic number.

It is not a de Polignac number, because 20213111221 - 2³ = 20213111213 is a prime.

It is a super-2 number, since 2×20213111221² (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 = 20213111195 and 20213111204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20213111251) 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 15 ways as a sum of consecutive naturals, for example, 3659700 + ... + 3665218.

It is an arithmetic number, because the mean of its divisors is an integer number (1355518800).

Almost surely, 2^20213111221 is an apocalyptic number.

It is an amenable number.

20213111221 is a deficient number, since it is larger than the sum of its proper divisors (1475189579).

20213111221 is a wasteful number, since it uses less digits than its factorization.

20213111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9228.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 20213111221 its reverse (12211131202), we get a palindrome (32424242423).

The spelling of 20213111221 in words is "twenty billion, two hundred thirteen million, one hundred eleven thousand, two hundred twenty-one".