20021208011111 has 2 divisors, whose sum is σ = 20021208011112. Its totient is φ = 20021208011110.

The previous prime is 20021208011071. The next prime is 20021208011137. The reversal of 20021208011111 is 11111080212002.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021208011111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021208011171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010604005555 + 10010604005556.

It is an arithmetic number, because the mean of its divisors is an integer number (10010604005556).

Almost surely, 2^{20021208011111} is an apocalyptic number.

20021208011111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021208011111 is an equidigital number, since it uses as much as digits as its factorization.

20021208011111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 20021208011111 its reverse (11111080212002), we get a palindrome (31132288223113).

The spelling of 20021208011111 in words is "twenty trillion, twenty-one billion, two hundred eight million, eleven thousand, one hundred eleven".