123221221221 has 16 divisors (see below), whose sum is σ = 187790361728. Its totient is φ = 70402867200.

The previous prime is 123221221141. The next prime is 123221221243. The reversal of 123221221221 is 122122122321.

It is not a de Polignac number, because 123221221221 - 2⁹ = 123221220709 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123221229221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 220660 + ... + 543261.

It is an arithmetic number, because the mean of its divisors is an integer number (11736897608).

Almost surely, 2^123221221221 is an apocalyptic number.

It is an amenable number.

123221221221 is a deficient number, since it is larger than the sum of its proper divisors (64569140507).

123221221221 is an equidigital number, since it uses as much as digits as its factorization.

123221221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771612.

The product of its digits is 384, while the sum is 21.

Adding to 123221221221 its reverse (122122122321), we get a palindrome (245343343542).

The spelling of 123221221221 in words is "one hundred twenty-three billion, two hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".