20012111221111 has 2 divisors, whose sum is σ = 20012111221112. Its totient is φ = 20012111221110.

The previous prime is 20012111221073. The next prime is 20012111221139. The reversal of 20012111221111 is 11112211121002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20012111221111 - 2¹¹ = 20012111219063 is a prime.

It is a super-2 number, since 2×20012111221111² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20012111221171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10006055610555 + 10006055610556.

It is an arithmetic number, because the mean of its divisors is an integer number (10006055610556).

Almost surely, 2^{20012111221111} is an apocalyptic number.

20012111221111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20012111221111 is an equidigital number, since it uses as much as digits as its factorization.

20012111221111 is an evil number, because the sum of its binary digits is even.

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

Adding to 20012111221111 its reverse (11112211121002), we get a palindrome (31124322342113).

The spelling of 20012111221111 in words is "twenty trillion, twelve billion, one hundred eleven million, two hundred twenty-one thousand, one hundred eleven".