1221201101211 has 48 divisors (see below), whose sum is σ = 2121087939840. Its totient is φ = 610247364480.

The previous prime is 1221201101207. The next prime is 1221201101261. The reversal of 1221201101211 is 1121011021221.

It is a happy number.

It is not a de Polignac number, because 1221201101211 - 2² = 1221201101207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221201101201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8987760 + ... + 9122621.

It is an arithmetic number, because the mean of its divisors is an integer number (44189332080).

Almost surely, 2^{1221201101211} is an apocalyptic number.

1221201101211 is a deficient number, since it is larger than the sum of its proper divisors (899886838629).

1221201101211 is a wasteful number, since it uses less digits than its factorization.

1221201101211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18110436 (or 18110423 counting only the distinct ones).

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

Adding to 1221201101211 its reverse (1121011021221), we get a palindrome (2342212122432).

The spelling of 1221201101211 in words is "one trillion, two hundred twenty-one billion, two hundred one million, one hundred one thousand, two hundred eleven".