1221220202112 has 128 divisors (see below), whose sum is σ = 3606142680000. Its totient is φ = 406864806912.

The previous prime is 1221220202071. The next prime is 1221220202123. The reversal of 1221220202112 is 2112020221221.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6729139 + ... + 6908237.

Almost surely, 2^{1221220202112} is an apocalyptic number.

1221220202112 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221220202112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1803071340000).

1221220202112 is an abundant number, since it is smaller than the sum of its proper divisors (2384922477888).

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

1221220202112 is a wasteful number, since it uses less digits than its factorization.

1221220202112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181095 (or 181077 counting only the distinct ones).

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

Adding to 1221220202112 its reverse (2112020221221), we get a palindrome (3333240423333).

The spelling of 1221220202112 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, two hundred two thousand, one hundred twelve".