20121210211111 has 8 divisors (see below), whose sum is σ = 20168255758464. Its totient is φ = 20074171985400.

The previous prime is 20121210211043. The next prime is 20121210211121. The reversal of 20121210211111 is 11111201212102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20121210211111 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121210211121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3691830 + ... + 7339756.

It is an arithmetic number, because the mean of its divisors is an integer number (2521031969808).

Almost surely, 2^{20121210211111} is an apocalyptic number.

20121210211111 is a deficient number, since it is larger than the sum of its proper divisors (47045547353).

20121210211111 is a wasteful number, since it uses less digits than its factorization.

20121210211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3660821.

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

Adding to 20121210211111 its reverse (11111201212102), we get a palindrome (31232411423213).

It can be divided in two parts, 201212102 and 11111, that multiplied together give a palindrome (2235667665322).

The spelling of 20121210211111 in words is "twenty trillion, one hundred twenty-one billion, two hundred ten million, two hundred eleven thousand, one hundred eleven".