172320 has 48 divisors (see below), whose sum is σ = 544320. Its totient is φ = 45824.

The previous prime is 172313. The next prime is 172321. The reversal of 172320 is 23271.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 172320.

It is not an unprimeable number, because it can be changed into a prime (172321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 301 + ... + 659.

It is an arithmetic number, because the mean of its divisors is an integer number (11340).

2¹⁷²³²⁰ is an apocalyptic number.

172320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

172320 is the 240-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272160).

172320 is an abundant number, since it is smaller than the sum of its proper divisors (372000).

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

172320 is a wasteful number, since it uses less digits than its factorization.

172320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377 (or 369 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 172320 is about 415.1144420518. The cubic root of 172320 is about 55.6474449673.

Adding to 172320 its reverse (23271), we get a palindrome (195591).

The spelling of 172320 in words is "one hundred seventy-two thousand, three hundred twenty", and thus it is an iban number.