20002171 has 4 divisors (see below), whose sum is σ = 22859632. Its totient is φ = 17144712.

The previous prime is 20002159. The next prime is 20002187. The reversal of 20002171 is 17120002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17120002 = 2 ⋅8560001.

It is a cyclic number.

It is not a de Polignac number, because 20002171 - 2⁹ = 20001659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20002771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1428720 + ... + 1428733.

It is an arithmetic number, because the mean of its divisors is an integer number (5714908).

Almost surely, 2^20002171 is an apocalyptic number.

20002171 is a deficient number, since it is larger than the sum of its proper divisors (2857461).

20002171 is an equidigital number, since it uses as much as digits as its factorization.

20002171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2857460.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 20002171 is about 4472.3786735919. The cubic root of 20002171 is about 271.4515829719.

Adding to 20002171 its reverse (17120002), we get a palindrome (37122173).

The spelling of 20002171 in words is "twenty million, two thousand, one hundred seventy-one".