180817920 has 260 divisors, whose sum is σ = 654133260. Its totient is φ = 47775744.

The previous prime is 180817891. The next prime is 180817921. The reversal of 180817920 is 29718081.

It can be written as a sum of positive squares in 2 ways, for example, as 95883264 + 84934656 = 9792^2 + 9216^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (180817921) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1658826 + ... + 1658934.

Almost surely, 2^180817920 is an apocalyptic number.

180817920 is a gapful number since it is divisible by the number (10) 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 180817920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327066630).

180817920 is an abundant number, since it is smaller than the sum of its proper divisors (473315340).

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

180817920 is an equidigital number, since it uses as much as digits as its factorization.

180817920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 180817920 is about 13446.8553944779. The cubic root of 180817920 is about 565.4755387684.

The spelling of 180817920 in words is "one hundred eighty million, eight hundred seventeen thousand, nine hundred twenty".