1221100221012 has 48 divisors (see below), whose sum is σ = 3344274487680. Its totient is φ = 339456431232.

The previous prime is 1221100221007. The next prime is 1221100221043. The reversal of 1221100221012 is 2101220011221.

It is a junction number, because it is equal to n+sod(n) for n = 1221100220982 and 1221100221000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 196441587 + ... + 196447802.

It is an arithmetic number, because the mean of its divisors is an integer number (69672385160).

Almost surely, 2^{1221100221012} is an apocalyptic number.

1221100221012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221100221012 is an abundant number, since it is smaller than the sum of its proper divisors (2123174266668).

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

1221100221012 is a wasteful number, since it uses less digits than its factorization.

1221100221012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392889440 (or 392889438 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221100221012 its reverse (2101220011221), we get a palindrome (3322320232233).

The spelling of 1221100221012 in words is "one trillion, two hundred twenty-one billion, one hundred million, two hundred twenty-one thousand, twelve".