1221101100012 has 48 divisors (see below), whose sum is σ = 2999449474560. Its totient is φ = 385578243648.

The previous prime is 1221101099989. The next prime is 1221101100013. The reversal of 1221101100012 is 2100011011221.

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

It is not an unprimeable number, because it can be changed into a prime (1221101100013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2548078 + ... + 2989130.

It is an arithmetic number, because the mean of its divisors is an integer number (62488530720).

Almost surely, 2^{1221101100012} is an apocalyptic number.

1221101100012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221101100012 is an abundant number, since it is smaller than the sum of its proper divisors (1778348374548).

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

1221101100012 is a wasteful number, since it uses less digits than its factorization.

1221101100012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453222 (or 453220 counting only the distinct ones).

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

Adding to 1221101100012 its reverse (2100011011221), we get a palindrome (3321112111233).

The spelling of 1221101100012 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one hundred thousand, twelve".