1221100020011 has 6 divisors (see below), whose sum is σ = 1239597418500. Its totient is φ = 1202874642156.

The previous prime is 1221100019999. The next prime is 1221100020013. The reversal of 1221100020011 is 1100200011221.

It is not a de Polignac number, because 1221100020011 - 2³⁰ = 1220026278187 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221100019974 and 1221100020001.

It is not an unprimeable number, because it can be changed into a prime (1221100020013) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 136005761 + ... + 136014738.

It is an arithmetic number, because the mean of its divisors is an integer number (206599569750).

Almost surely, 2^{1221100020011} is an apocalyptic number.

1221100020011 is a deficient number, since it is larger than the sum of its proper divisors (18497398489).

1221100020011 is an frugal number, since it uses more digits than its factorization.

1221100020011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272020633 (or 272020566 counting only the distinct ones).

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

Adding to 1221100020011 its reverse (1100200011221), we get a palindrome (2321300031232).

The spelling of 1221100020011 in words is "one trillion, two hundred twenty-one billion, one hundred million, twenty thousand, eleven".