1221212002120 has 128 divisors (see below), whose sum is σ = 3007990702080. Its totient is φ = 442528480000.

The previous prime is 1221212002103. The next prime is 1221212002133. The reversal of 1221212002120 is 212002121221.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1221212002094 and 1221212002103.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 186412845 + ... + 186419395.

It is an arithmetic number, because the mean of its divisors is an integer number (23499927360).

Almost surely, 2^{1221212002120} is an apocalyptic number.

1221212002120 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 1221212002120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1503995351040).

1221212002120 is an abundant number, since it is smaller than the sum of its proper divisors (1786778699960).

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

1221212002120 is a wasteful number, since it uses less digits than its factorization.

1221212002120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7987 (or 7983 counting only the distinct ones).

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

Adding to 1221212002120 its reverse (212002121221), we get a palindrome (1433214123341).

The spelling of 1221212002120 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two thousand, one hundred twenty".