1221000001101 has 8 divisors (see below), whose sum is σ = 1808888890560. Its totient is φ = 814000000716.

The previous prime is 1221000001063. The next prime is 1221000001171. The reversal of 1221000001101 is 1011000001221.

It is a happy number.

It is not a de Polignac number, because 1221000001101 - 2⁶ = 1221000001037 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000001171) 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 7 ways as a sum of consecutive naturals, for example, 22611111105 + ... + 22611111158.

It is an arithmetic number, because the mean of its divisors is an integer number (226111111320).

Almost surely, 2^{1221000001101} is an apocalyptic number.

It is an amenable number.

1221000001101 is a deficient number, since it is larger than the sum of its proper divisors (587888889459).

1221000001101 is an equidigital number, since it uses as much as digits as its factorization.

1221000001101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45222222272 (or 45222222266 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1221000001101 its reverse (1011000001221), we get a palindrome (2232000002322).

The spelling of 1221000001101 in words is "one trillion, two hundred twenty-one billion, one thousand, one hundred one".