1221002102000 has 80 divisors (see below), whose sum is σ = 2958302100000. Its totient is φ = 487421683200.

The previous prime is 1221002101997. The next prime is 1221002102029. The reversal of 1221002102000 is 2012001221.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×1221002102000² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 386276 + ... + 1609724.

It is an arithmetic number, because the mean of its divisors is an integer number (36978776250).

Almost surely, 2^{1221002102000} is an apocalyptic number.

1221002102000 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 1221002102000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1479151050000).

1221002102000 is an abundant number, since it is smaller than the sum of its proper divisors (1737299998000).

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

1221002102000 is a wasteful number, since it uses less digits than its factorization.

1221002102000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1223971 (or 1223955 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 1221002102000 its reverse (2012001221), we get a palindrome (1223014103221).

The spelling of 1221002102000 in words is "one trillion, two hundred twenty-one billion, two million, one hundred two thousand".