1221101001011 has 4 divisors (see below), whose sum is σ = 1221325349832. Its totient is φ = 1220876652192.

The previous prime is 1221101000957. The next prime is 1221101001049. The reversal of 1221101001011 is 1101001011221.

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 1221101001011 - 2⁶ = 1221101000947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221101000983 and 1221101001001.

It is not an unprimeable number, because it can be changed into a prime (1221101001511) 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, 112166246 + ... + 112177131.

It is an arithmetic number, because the mean of its divisors is an integer number (305331337458).

Almost surely, 2^{1221101001011} is an apocalyptic number.

1221101001011 is a deficient number, since it is larger than the sum of its proper divisors (224348821).

1221101001011 is an equidigital number, since it uses as much as digits as its factorization.

1221101001011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224348820.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1221101001011 its reverse (1101001011221), we get a palindrome (2322102012232).

The spelling of 1221101001011 in words is "one trillion, two hundred twenty-one billion, one hundred one million, one thousand, eleven".