1211222001220 has 384 divisors, whose sum is σ = 3490081136640. Its totient is φ = 341432340480.

The previous prime is 1211222001217. The next prime is 1211222001281. The reversal of 1211222001220 is 221002221121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1211222001194 and 1211222001203.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 415227202 + ... + 415230118.

It is an arithmetic number, because the mean of its divisors is an integer number (9088752960).

Almost surely, 2^{1211222001220} is an apocalyptic number.

1211222001220 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 1211222001220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1745040568320).

1211222001220 is an abundant number, since it is smaller than the sum of its proper divisors (2278859135420).

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

1211222001220 is a wasteful number, since it uses less digits than its factorization.

1211222001220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3603 (or 3601 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1211222001220 its reverse (221002221121), we get a palindrome (1432224222341).

The spelling of 1211222001220 in words is "one trillion, two hundred eleven billion, two hundred twenty-two million, one thousand, two hundred twenty".