1211120111021 has 4 divisors (see below), whose sum is σ = 1252882873500. Its totient is φ = 1169357348544.

The previous prime is 1211120111009. The next prime is 1211120111039. The reversal of 1211120111021 is 1201110211121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 380991390025 + 830128720996 = 617245^2 + 911114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211120111021 - 2²⁶ = 1211053002157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211120110987 and 1211120111005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211120111081) 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, 20881381196 + ... + 20881381253.

It is an arithmetic number, because the mean of its divisors is an integer number (313220718375).

Almost surely, 2^{1211120111021} is an apocalyptic number.

It is an amenable number.

1211120111021 is a deficient number, since it is larger than the sum of its proper divisors (41762762479).

1211120111021 is an equidigital number, since it uses as much as digits as its factorization.

1211120111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41762762478.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 1211120111021 its reverse (1201110211121), we get a palindrome (2412230322142).

The spelling of 1211120111021 in words is "one trillion, two hundred eleven billion, one hundred twenty million, one hundred eleven thousand, twenty-one".