20121212171 has 2 divisors, whose sum is σ = 20121212172. Its totient is φ = 20121212170.

The previous prime is 20121212117. The next prime is 20121212183. The reversal of 20121212171 is 17121212102.

It is a happy number.

Together with previous prime (20121212117) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20121212171 - 2²² = 20117017867 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121211171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060606085 + 10060606086.

It is an arithmetic number, because the mean of its divisors is an integer number (10060606086).

Almost surely, 2^20121212171 is an apocalyptic number.

20121212171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121212171 is an equidigital number, since it uses as much as digits as its factorization.

20121212171 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20121212171 its reverse (17121212102), we get a palindrome (37242424273).

The spelling of 20121212171 in words is "twenty billion, one hundred twenty-one million, two hundred twelve thousand, one hundred seventy-one".