20001210121111 has 2 divisors, whose sum is σ = 20001210121112. Its totient is φ = 20001210121110.

The previous prime is 20001210121099. The next prime is 20001210121133. The reversal of 20001210121111 is 11112101210002.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20001210121111 - 2⁹ = 20001210120599 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001210121091 and 20001210121100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001210121181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000605060555 + 10000605060556.

It is an arithmetic number, because the mean of its divisors is an integer number (10000605060556).

Almost surely, 2^{20001210121111} is an apocalyptic number.

20001210121111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001210121111 is an equidigital number, since it uses as much as digits as its factorization.

20001210121111 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20001210121111 its reverse (11112101210002), we get a palindrome (31113311331113).

The spelling of 20001210121111 in words is "twenty trillion, one billion, two hundred ten million, one hundred twenty-one thousand, one hundred eleven".