20171880 has 96 divisors (see below), whose sum is σ = 66198600. Its totient is φ = 5326848.

The previous prime is 20171873. The next prime is 20171887. The reversal of 20171880 is 8817102.

It is an interprime number because it is at equal distance from previous prime (20171873) and next prime (20171887).

It can be written as a sum of positive squares in 4 ways, for example, as 19554084 + 617796 = 4422^2 + 786^2 .

It is not an unprimeable number, because it can be changed into a prime (20171887) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49116 + ... + 49524.

Almost surely, 2^20171880 is an apocalyptic number.

20171880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20171880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33099300).

20171880 is an abundant number, since it is smaller than the sum of its proper divisors (46026720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20171880 is a wasteful number, since it uses less digits than its factorization.

20171880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 556 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20171880 is about 4491.3116124357. The cubic root of 20171880 is about 272.2171348641.

Adding to 20171880 its reverse (8817102), we get a palindrome (28988982).

The spelling of 20171880 in words is "twenty million, one hundred seventy-one thousand, eight hundred eighty".