1221202221011 has 4 divisors (see below), whose sum is σ = 1241900563800. Its totient is φ = 1200503878224.

The previous prime is 1221202220969. The next prime is 1221202221047. The reversal of 1221202221011 is 1101222021221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221202221011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221202221061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10349171306 + ... + 10349171423.

It is an arithmetic number, because the mean of its divisors is an integer number (310475140950).

Almost surely, 2^{1221202221011} is an apocalyptic number.

1221202221011 is a deficient number, since it is larger than the sum of its proper divisors (20698342789).

1221202221011 is an equidigital number, since it uses as much as digits as its factorization.

1221202221011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20698342788.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221202221011 its reverse (1101222021221), we get a palindrome (2322424242232).

The spelling of 1221202221011 in words is "one trillion, two hundred twenty-one billion, two hundred two million, two hundred twenty-one thousand, eleven".