1221001121211 has 8 divisors (see below), whose sum is σ = 1672001535504. Its totient is φ = 792000727200.

The previous prime is 1221001121201. The next prime is 1221001121227. The reversal of 1221001121211 is 1121211001221.

It is a happy number.

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

It is not a de Polignac number, because 1221001121211 - 2²¹ = 1220999024059 is a prime.

It is a super-2 number, since 2×1221001121211² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221001121201) 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, 5500004940 + ... + 5500005161.

It is an arithmetic number, because the mean of its divisors is an integer number (209000191938).

Almost surely, 2^{1221001121211} is an apocalyptic number.

1221001121211 is a deficient number, since it is larger than the sum of its proper divisors (451000414293).

1221001121211 is a wasteful number, since it uses less digits than its factorization.

1221001121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11000010141.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221001121211 its reverse (1121211001221), we get a palindrome (2342212122432).

The spelling of 1221001121211 in words is "one trillion, two hundred twenty-one billion, one million, one hundred twenty-one thousand, two hundred eleven".