20021012171 has 2 divisors, whose sum is σ = 20021012172. Its totient is φ = 20021012170.

The previous prime is 20021012161. The next prime is 20021012173. The reversal of 20021012171 is 17121012002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20021012171 - 2³⁴ = 2841142987 is a prime.

Together with 20021012173, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20021012173) 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, 10010506085 + 10010506086.

It is an arithmetic number, because the mean of its divisors is an integer number (10010506086).

Almost surely, 2^20021012171 is an apocalyptic number.

20021012171 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021012171 is an equidigital number, since it uses as much as digits as its factorization.

20021012171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 17.

Adding to 20021012171 its reverse (17121012002), we get a palindrome (37142024173).

The spelling of 20021012171 in words is "twenty billion, twenty-one million, twelve thousand, one hundred seventy-one".