20171123 has 4 divisors (see below), whose sum is σ = 23052720. Its totient is φ = 17289528.

The previous prime is 20171101. The next prime is 20171147. The reversal of 20171123 is 32117102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20171123 - 2⁸ = 20170867 is a prime.

It is a super-2 number, since 2×20171123² = 813748406162258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20171423) 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, 1440788 + ... + 1440801.

It is an arithmetic number, because the mean of its divisors is an integer number (5763180).

Almost surely, 2^20171123 is an apocalyptic number.

20171123 is a deficient number, since it is larger than the sum of its proper divisors (2881597).

20171123 is an equidigital number, since it uses as much as digits as its factorization.

20171123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2881596.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 20171123 is about 4491.2273378220. The cubic root of 20171123 is about 272.2137296130.

Adding to 20171123 its reverse (32117102), we get a palindrome (52288225).

The spelling of 20171123 in words is "twenty million, one hundred seventy-one thousand, one hundred twenty-three".