20121001211111 has 2 divisors, whose sum is σ = 20121001211112. Its totient is φ = 20121001211110.

The previous prime is 20121001211081. The next prime is 20121001211149. The reversal of 20121001211111 is 11111210012102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20121001211111 - 2¹⁴ = 20121001194727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121001211711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060500605555 + 10060500605556.

It is an arithmetic number, because the mean of its divisors is an integer number (10060500605556).

Almost surely, 2^{20121001211111} is an apocalyptic number.

20121001211111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121001211111 is an equidigital number, since it uses as much as digits as its factorization.

20121001211111 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 14.

Adding to 20121001211111 its reverse (11111210012102), we get a palindrome (31232211223213).

The spelling of 20121001211111 in words is "twenty trillion, one hundred twenty-one billion, one million, two hundred eleven thousand, one hundred eleven".