1221102011 has 2 divisors, whose sum is σ = 1221102012. Its totient is φ = 1221102010.

The previous prime is 1221102007. The next prime is 1221102023. The reversal of 1221102011 is 1102011221.

It is a weak prime.

It is an emirp because it is prime and its reverse (1102011221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221102011 - 2² = 1221102007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221101983 and 1221102001.

It is not a weakly prime, because it can be changed into another prime (1221102041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610551005 + 610551006.

It is an arithmetic number, because the mean of its divisors is an integer number (610551006).

Almost surely, 2^1221102011 is an apocalyptic number.

1221102011 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221102011 is an equidigital number, since it uses as much as digits as its factorization.

1221102011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1221102011 is about 34944.2700739334. The cubic root of 1221102011 is about 1068.8513632484.

Adding to 1221102011 its reverse (1102011221), we get a palindrome (2323113232).

The spelling of 1221102011 in words is "one billion, two hundred twenty-one million, one hundred two thousand, eleven".