1211221121011 has 8 divisors (see below), whose sum is σ = 1342993315248. Its totient is φ = 1083059124000.

The previous prime is 1211221120981. The next prime is 1211221121017. The reversal of 1211221121011 is 1101211221121.

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 1211221121011 - 2¹⁵ = 1211221088243 is a prime.

It is a super-3 number, since 3×1211221121011³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211221121017) 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, 902548600 + ... + 902549941.

It is an arithmetic number, because the mean of its divisors is an integer number (167874164406).

Almost surely, 2^{1211221121011} is an apocalyptic number.

1211221121011 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1211221121011 is a deficient number, since it is larger than the sum of its proper divisors (131772194237).

1211221121011 is a wasteful number, since it uses less digits than its factorization.

1211221121011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1805098613.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1211221121011 its reverse (1101211221121), we get a palindrome (2312432342132).

The spelling of 1211221121011 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, eleven".