20171121 has 8 divisors (see below), whose sum is σ = 26917920. Its totient is φ = 13435872.

The previous prime is 20171101. The next prime is 20171147. The reversal of 20171121 is 12117102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20171121 - 2⁵ = 20171089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20171121.

It is not an unprimeable number, because it can be changed into a prime (20171101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2781 + ... + 6933.

It is an arithmetic number, because the mean of its divisors is an integer number (3364740).

Almost surely, 2^20171121 is an apocalyptic number.

It is an amenable number.

20171121 is a deficient number, since it is larger than the sum of its proper divisors (6746799).

20171121 is a wasteful number, since it uses less digits than its factorization.

20171121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5775.

The product of its (nonzero) digits is 28, while the sum is 15.

The square root of 20171121 is about 4491.2271151657. The cubic root of 20171121 is about 272.2137206162.

Adding to 20171121 its reverse (12117102), we get a palindrome (32288223).

The spelling of 20171121 in words is "twenty million, one hundred seventy-one thousand, one hundred twenty-one".