1211021220111 has 16 divisors (see below), whose sum is σ = 1619840345088. Its totient is φ = 804775593600.

The previous prime is 1211021220023. The next prime is 1211021220163. The reversal of 1211021220111 is 1110221201121.

It is a happy number.

It is not a de Polignac number, because 1211021220111 - 2⁹ = 1211021219599 is a prime.

It is a super-2 number, since 2×1211021220111² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211021222111) 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, 6115746 + ... + 6310656.

It is an arithmetic number, because the mean of its divisors is an integer number (101240021568).

Almost surely, 2^{1211021220111} is an apocalyptic number.

1211021220111 is a deficient number, since it is larger than the sum of its proper divisors (408819124977).

1211021220111 is a wasteful number, since it uses less digits than its factorization.

1211021220111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201502.

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

Adding to 1211021220111 its reverse (1110221201121), we get a palindrome (2321242421232).

The spelling of 1211021220111 in words is "one trillion, two hundred eleven billion, twenty-one million, two hundred twenty thousand, one hundred eleven".