20231211221 has 12 divisors (see below), whose sum is σ = 21911617728. Its totient is φ = 18671172624.

The previous prime is 20231211211. The next prime is 20231211283. The reversal of 20231211221 is 12211213202.

It is not a de Polignac number, because 20231211221 - 2⁶ = 20231211157 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20231211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20231211211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1151126 + ... + 1168568.

It is an arithmetic number, because the mean of its divisors is an integer number (1825968144).

Almost surely, 2^20231211221 is an apocalyptic number.

It is an amenable number.

20231211221 is a deficient number, since it is larger than the sum of its proper divisors (1680406507).

20231211221 is a wasteful number, since it uses less digits than its factorization.

20231211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24332 (or 24319 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 20231211221 its reverse (12211213202), we get a palindrome (32442424423).

The spelling of 20231211221 in words is "twenty billion, two hundred thirty-one million, two hundred eleven thousand, two hundred twenty-one".