21123201222 has 24 divisors (see below), whose sum is σ = 47462008776. Its totient is φ = 7041066912.

The previous prime is 21123201157. The next prime is 21123201223. The reversal of 21123201222 is 22210232112.

21123201222 is a `hidden beast` number, since 211 + 232 + 0 + 1 + 222 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21123201195 and 21123201204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123201223) 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 11 ways as a sum of consecutive naturals, for example, 21731203 + ... + 21732174.

It is an arithmetic number, because the mean of its divisors is an integer number (1977583699).

Almost surely, 2^21123201222 is an apocalyptic number.

21123201222 is an abundant number, since it is smaller than the sum of its proper divisors (26338807554).

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

21123201222 is an equidigital number, since it uses as much as digits as its factorization.

21123201222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43463394 (or 43463382 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21123201222 its reverse (22210232112), we get a palindrome (43333433334).

The spelling of 21123201222 in words is "twenty-one billion, one hundred twenty-three million, two hundred one thousand, two hundred twenty-two".