20172880 has 160 divisors (see below), whose sum is σ = 61496064. Its totient is φ = 5971968.

The previous prime is 20172877. The next prime is 20172941. The reversal of 20172880 is 8827102.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 123679 + ... + 123841.

Almost surely, 2^20172880 is an apocalyptic number.

20172880 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 20172880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30748032).

20172880 is an abundant number, since it is smaller than the sum of its proper divisors (41323184).

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

20172880 is a wasteful number, since it uses less digits than its factorization.

20172880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 20172880 is about 4491.4229371102. The cubic root of 20172880 is about 272.2216330837.

Adding to 20172880 its reverse (8827102), we get a palindrome (28999982).

The spelling of 20172880 in words is "twenty million, one hundred seventy-two thousand, eight hundred eighty".