1211210111011 has 4 divisors (see below), whose sum is σ = 1211253577912. Its totient is φ = 1211166644112.

The previous prime is 1211210110973. The next prime is 1211210111021. The reversal of 1211210111011 is 1101110121121.

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 1211210111011 - 2⁹ = 1211210110499 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211210110982 and 1211210111000.

It is not an unprimeable number, because it can be changed into a prime (1211210111021) 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, 21691626 + ... + 21747391.

It is an arithmetic number, because the mean of its divisors is an integer number (302813394478).

Almost surely, 2^{1211210111011} is an apocalyptic number.

1211210111011 is a deficient number, since it is larger than the sum of its proper divisors (43466901).

1211210111011 is an equidigital number, since it uses as much as digits as its factorization.

1211210111011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43466900.

The product of its (nonzero) digits is 4, while the sum is 13.

Adding to 1211210111011 its reverse (1101110121121), we get a palindrome (2312320232132).

The spelling of 1211210111011 in words is "one trillion, two hundred eleven billion, two hundred ten million, one hundred eleven thousand, eleven".