20152171 has 4 divisors (see below), whose sum is σ = 21702352. Its totient is φ = 18601992.

The previous prime is 20152169. The next prime is 20152177. The reversal of 20152171 is 17125102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17125102 = 2 ⋅8562551.

It is a cyclic number.

It is not a de Polignac number, because 20152171 - 2¹ = 20152169 is a prime.

It is a super-2 number, since 2×20152171² = 812219992026482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20152177) 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 in 3 ways as a sum of consecutive naturals, for example, 775071 + ... + 775096.

It is an arithmetic number, because the mean of its divisors is an integer number (5425588).

Almost surely, 2^20152171 is an apocalyptic number.

20152171 is a deficient number, since it is larger than the sum of its proper divisors (1550181).

20152171 is a wasteful number, since it uses less digits than its factorization.

20152171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1550180.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 20152171 is about 4489.1169510272. The cubic root of 20152171 is about 272.1284490996.

Adding to 20152171 its reverse (17125102), we get a palindrome (37277273).

It can be divided in two parts, 2015 and 2171, that added together give a triangular number (4186 = T₉₁).

The spelling of 20152171 in words is "twenty million, one hundred fifty-two thousand, one hundred seventy-one".