20200121120171 has 2 divisors, whose sum is σ = 20200121120172. Its totient is φ = 20200121120170.

The previous prime is 20200121120143. The next prime is 20200121120189. The reversal of 20200121120171 is 17102112100202.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20200121120171 - 2²² = 20200116925867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20200121122171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100060560085 + 10100060560086.

It is an arithmetic number, because the mean of its divisors is an integer number (10100060560086).

Almost surely, 2^{20200121120171} is an apocalyptic number.

20200121120171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20200121120171 is an equidigital number, since it uses as much as digits as its factorization.

20200121120171 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 20200121120171 its reverse (17102112100202), we get a palindrome (37302233220373).

The spelling of 20200121120171 in words is "twenty trillion, two hundred billion, one hundred twenty-one million, one hundred twenty thousand, one hundred seventy-one".