1221022211 has 4 divisors (see below), whose sum is σ = 1223659872. Its totient is φ = 1218384552.

The previous prime is 1221022193. The next prime is 1221022223. The reversal of 1221022211 is 1122201221.

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 1221022211 - 2²⁶ = 1153913347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221022111) 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, 1318136 + ... + 1319061.

It is an arithmetic number, because the mean of its divisors is an integer number (305914968).

Almost surely, 2^1221022211 is an apocalyptic number.

1221022211 is a deficient number, since it is larger than the sum of its proper divisors (2637661).

1221022211 is an equidigital number, since it uses as much as digits as its factorization.

1221022211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2637660.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1221022211 is about 34943.1282371799. The cubic root of 1221022211 is about 1068.8280793087.

Adding to 1221022211 its reverse (1122201221), we get a palindrome (2343223432).

The spelling of 1221022211 in words is "one billion, two hundred twenty-one million, twenty-two thousand, two hundred eleven".