1221021211211 has 8 divisors (see below), whose sum is σ = 1223986762320. Its totient is φ = 1218055905792.

The previous prime is 1221021211177. The next prime is 1221021211231. The reversal of 1221021211211 is 1121121201221.

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 1221021211211 - 2⁶ = 1221021211147 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 1221021211211.

It is not an unprimeable number, because it can be changed into a prime (1221021211231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13510871 + ... + 13600943.

It is an arithmetic number, because the mean of its divisors is an integer number (152998345290).

Almost surely, 2^{1221021211211} is an apocalyptic number.

1221021211211 is a deficient number, since it is larger than the sum of its proper divisors (2965551109).

1221021211211 is an equidigital number, since it uses as much as digits as its factorization.

1221021211211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122845.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221021211211 its reverse (1121121201221), we get a palindrome (2342142412432).

The spelling of 1221021211211 in words is "one trillion, two hundred twenty-one billion, twenty-one million, two hundred eleven thousand, two hundred eleven".