1221102211011 has 4 divisors (see below), whose sum is σ = 1628136281352. Its totient is φ = 814068140672.

The previous prime is 1221102210989. The next prime is 1221102211019. The reversal of 1221102211011 is 1101122011221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221102211011 - 2⁷ = 1221102210883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221102211019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203517035166 + ... + 203517035171.

It is an arithmetic number, because the mean of its divisors is an integer number (407034070338).

Almost surely, 2^{1221102211011} is an apocalyptic number.

1221102211011 is a deficient number, since it is larger than the sum of its proper divisors (407034070341).

1221102211011 is an equidigital number, since it uses as much as digits as its factorization.

1221102211011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407034070340.

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

Adding to 1221102211011 its reverse (1101122011221), we get a palindrome (2322224222232).

The spelling of 1221102211011 in words is "one trillion, two hundred twenty-one billion, one hundred two million, two hundred eleven thousand, eleven".