1221221012211 has 12 divisors (see below), whose sum is σ = 1811661201792. Its totient is φ = 792143359056.

The previous prime is 1221221012203. The next prime is 1221221012257. The reversal of 1221221012211 is 1122101221221.

1221221012211 is a `hidden beast` number, since 1 + 221 + 221 + 0 + 1 + 221 + 1 = 666.

It is not a de Polignac number, because 1221221012211 - 2³ = 1221221012203 is a prime.

It is a super-2 number, since 2×1221221012211² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221221012911) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1833664851 + ... + 1833665516.

It is an arithmetic number, because the mean of its divisors is an integer number (150971766816).

Almost surely, 2^{1221221012211} is an apocalyptic number.

1221221012211 is a deficient number, since it is larger than the sum of its proper divisors (590440189581).

1221221012211 is a wasteful number, since it uses less digits than its factorization.

1221221012211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3667330410 (or 3667330407 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221221012211 its reverse (1122101221221), we get a palindrome (2343322233432).

The spelling of 1221221012211 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-one million, twelve thousand, two hundred eleven".