1221100011012 has 72 divisors (see below), whose sum is σ = 3314629400544. Its totient is φ = 348863077248.

The previous prime is 1221100011007. The next prime is 1221100011031. The reversal of 1221100011012 is 2101100011221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10376728 + ... + 10493744.

It is an arithmetic number, because the mean of its divisors is an integer number (46036519452).

Almost surely, 2^{1221100011012} is an apocalyptic number.

1221100011012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221100011012 is an abundant number, since it is smaller than the sum of its proper divisors (2093529389532).

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

1221100011012 is a wasteful number, since it uses less digits than its factorization.

1221100011012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134785 (or 134776 counting only the distinct ones).

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

Adding to 1221100011012 its reverse (2101100011221), we get a palindrome (3322200022233).

The spelling of 1221100011012 in words is "one trillion, two hundred twenty-one billion, one hundred million, eleven thousand, twelve".