221220121122 has 192 divisors, whose sum is σ = 644385530880. Its totient is φ = 52970889600.

The previous prime is 221220121061. The next prime is 221220121127. The reversal of 221220121122 is 221121022122.

It is a happy number.

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 = 221220121095 and 221220121104.

It is not an unprimeable number, because it can be changed into a prime (221220121127) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 14605029 + ... + 14620167.

It is an arithmetic number, because the mean of its divisors is an integer number (3356174640).

Almost surely, 2^221220121122 is an apocalyptic number.

221220121122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 221220121122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322192765440).

221220121122 is an abundant number, since it is smaller than the sum of its proper divisors (423165409758).

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

221220121122 is a wasteful number, since it uses less digits than its factorization.

221220121122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15989 (or 15986 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221220121122 its reverse (221121022122), we get a palindrome (442341143244).

The spelling of 221220121122 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, one hundred twenty-two".