1221100111002 has 64 divisors (see below), whose sum is σ = 2566301460480. Its totient is φ = 386600808000.

The previous prime is 1221100111001. The next prime is 1221100111003. The reversal of 1221100111002 is 2001110011221.

It is an interprime number because it is at equal distance from previous prime (1221100111001) and next prime (1221100111003).

It is not an unprimeable number, because it can be changed into a prime (1221100111001) by changing a digit.

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, 58106677 + ... + 58127687.

It is an arithmetic number, because the mean of its divisors is an integer number (40098460320).

Almost surely, 2^{1221100111002} is an apocalyptic number.

1221100111002 is an abundant number, since it is smaller than the sum of its proper divisors (1345201349478).

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

1221100111002 is a wasteful number, since it uses less digits than its factorization.

1221100111002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23979.

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

Adding to 1221100111002 its reverse (2001110011221), we get a palindrome (3222210122223).

The spelling of 1221100111002 in words is "one trillion, two hundred twenty-one billion, one hundred million, one hundred eleven thousand, two".