20211223305 has 192 divisors, whose sum is σ = 42967895040. Its totient is φ = 8018486784.

The previous prime is 20211223273. The next prime is 20211223309. The reversal of 20211223305 is 50332211202.

It is not a de Polignac number, because 20211223305 - 2⁵ = 20211223273 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (20211223309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 29591494 + ... + 29592176.

It is an arithmetic number, because the mean of its divisors is an integer number (223791120).

Almost surely, 2^20211223305 is an apocalyptic number.

It is an amenable number.

20211223305 is an abundant number, since it is smaller than the sum of its proper divisors (22756671735).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20211223305 is a wasteful number, since it uses less digits than its factorization.

20211223305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900 (or 893 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

Adding to 20211223305 its reverse (50332211202), we get a palindrome (70543434507).

The spelling of 20211223305 in words is "twenty billion, two hundred eleven million, two hundred twenty-three thousand, three hundred five".