1221111010002 has 128 divisors (see below), whose sum is σ = 2729156935680. Its totient is φ = 361705201920.

The previous prime is 1221111009947. The next prime is 1221111010037. The reversal of 1221111010002 is 2000101111221.

It is a super-2 number, since 2×1221111010002² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221111010002.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 545381199 + ... + 545383437.

It is an arithmetic number, because the mean of its divisors is an integer number (21321538560).

Almost surely, 2^{1221111010002} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221111010002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1364578467840).

1221111010002 is an abundant number, since it is smaller than the sum of its proper divisors (1508045925678).

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

1221111010002 is a wasteful number, since it uses less digits than its factorization.

1221111010002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3368.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221111010002 its reverse (2000101111221), we get a palindrome (3221212121223).

The spelling of 1221111010002 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, ten thousand, two".