1221020011200 has 336 divisors, whose sum is σ = 4384163074176. Its totient is φ = 295055155200.

The previous prime is 1221020011181. The next prime is 1221020011201. The reversal of 1221020011200 is 21100201221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1221020011201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16489459 + ... + 16563341.

Almost surely, 2^{1221020011200} is an apocalyptic number.

1221020011200 is a gapful number since it is divisible by the number (10) 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 1221020011200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2192081537088).

1221020011200 is an abundant number, since it is smaller than the sum of its proper divisors (3163143062976).

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

1221020011200 is a wasteful number, since it uses less digits than its factorization.

1221020011200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74232 (or 74217 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1221020011200 its reverse (21100201221), we get a palindrome (1242120212421).

The spelling of 1221020011200 in words is "one trillion, two hundred twenty-one billion, twenty million, eleven thousand, two hundred".