1211221211 has 8 divisors (see below), whose sum is σ = 1217099520. Its totient is φ = 1205352448.

The previous prime is 1211221199. The next prime is 1211221213. The reversal of 1211221211 is 1121221121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211221211 - 2²² = 1207026907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211221213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 419270 + ... + 422148.

It is an arithmetic number, because the mean of its divisors is an integer number (152137440).

Almost surely, 2^1211221211 is an apocalyptic number.

1211221211 is a deficient number, since it is larger than the sum of its proper divisors (5878309).

1211221211 is a wasteful number, since it uses less digits than its factorization.

1211221211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4773.

The product of its digits is 16, while the sum is 14.

The square root of 1211221211 is about 34802.6035089331. The cubic root of 1211221211 is about 1065.9606080130.

Adding to 1211221211 its reverse (1121221121), we get a palindrome (2332442332).

The spelling of 1211221211 in words is "one billion, two hundred eleven million, two hundred twenty-one thousand, two hundred eleven".