1211211220011 has 32 divisors (see below), whose sum is σ = 1802023614720. Its totient is φ = 718902397824.

The previous prime is 1211211219961. The next prime is 1211211220027. The reversal of 1211211220011 is 1100221121121.

It is a happy number.

It is not a de Polignac number, because 1211211220011 - 2²⁶ = 1211144111147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1211211220061) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4843941 + ... + 5087846.

It is an arithmetic number, because the mean of its divisors is an integer number (56313237960).

Almost surely, 2^{1211211220011} is an apocalyptic number.

1211211220011 is a deficient number, since it is larger than the sum of its proper divisors (590812394709).

1211211220011 is a wasteful number, since it uses less digits than its factorization.

1211211220011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9931915.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1211211220011 its reverse (1100221121121), we get a palindrome (2311432341132).

The spelling of 1211211220011 in words is "one trillion, two hundred eleven billion, two hundred eleven million, two hundred twenty thousand, eleven".