20121212117 has 2 divisors, whose sum is σ = 20121212118. Its totient is φ = 20121212116.

The previous prime is 20121212099. The next prime is 20121212171. The reversal of 20121212117 is 71121212102.

It is a happy number.

Together with next prime (20121212171) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20105538436 + 15673681 = 141794^2 + 3959^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121212117 - 2²⁰ = 20120163541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20121212317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060606058 + 10060606059.

It is an arithmetic number, because the mean of its divisors is an integer number (10060606059).

Almost surely, 2^20121212117 is an apocalyptic number.

It is an amenable number.

20121212117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121212117 is an equidigital number, since it uses as much as digits as its factorization.

20121212117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 20.

Adding to 20121212117 its reverse (71121212102), we get a palindrome (91242424219).

The spelling of 20121212117 in words is "twenty billion, one hundred twenty-one million, two hundred twelve thousand, one hundred seventeen".