1221220012211 has 4 divisors (see below), whose sum is σ = 1221423182424. Its totient is φ = 1221016842000.

The previous prime is 1221220012169. The next prime is 1221220012213. The reversal of 1221220012211 is 1122100221221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221220012211 - 2⁶ = 1221220012147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221220012211.

It is not an unprimeable number, because it can be changed into a prime (1221220012213) 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, 101576090 + ... + 101588111.

It is an arithmetic number, because the mean of its divisors is an integer number (305355795606).

Almost surely, 2^{1221220012211} is an apocalyptic number.

1221220012211 is a deficient number, since it is larger than the sum of its proper divisors (203170213).

1221220012211 is an equidigital number, since it uses as much as digits as its factorization.

1221220012211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203170212.

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

Adding to 1221220012211 its reverse (1122100221221), we get a palindrome (2343320233432).

The spelling of 1221220012211 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, twelve thousand, two hundred eleven".