1211020021111 has 2 divisors, whose sum is σ = 1211020021112. Its totient is φ = 1211020021110.

The previous prime is 1211020021109. The next prime is 1211020021129. The reversal of 1211020021111 is 1111200201121.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1211020021111 - 2¹ = 1211020021109 is a prime.

Together with 1211020021109, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1211020021091 and 1211020021100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211020021151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605510010555 + 605510010556.

It is an arithmetic number, because the mean of its divisors is an integer number (605510010556).

Almost surely, 2^{1211020021111} is an apocalyptic number.

1211020021111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211020021111 is an equidigital number, since it uses as much as digits as its factorization.

1211020021111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1211020021111 its reverse (1111200201121), we get a palindrome (2322220222232).

The spelling of 1211020021111 in words is "one trillion, two hundred eleven billion, twenty million, twenty-one thousand, one hundred eleven".