1221020112011 has 16 divisors (see below), whose sum is σ = 1456315200000. Its totient is φ = 1000952924928.

The previous prime is 1221020111963. The next prime is 1221020112017. The reversal of 1221020112011 is 1102110201221.

It is a cyclic number.

It is not a de Polignac number, because 1221020112011 - 2⁶ = 1221020111947 is a prime.

It is a super-2 number, since 2×1221020112011² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221020112017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 735740 + ... + 1727238.

It is an arithmetic number, because the mean of its divisors is an integer number (91019700000).

Almost surely, 2^{1221020112011} is an apocalyptic number.

1221020112011 is a deficient number, since it is larger than the sum of its proper divisors (235295087989).

1221020112011 is an equidigital number, since it uses as much as digits as its factorization.

1221020112011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999178.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1221020112011 its reverse (1102110201221), we get a palindrome (2323130313232).

The spelling of 1221020112011 in words is "one trillion, two hundred twenty-one billion, twenty million, one hundred twelve thousand, eleven".