172720 has 40 divisors (see below), whose sum is σ = 428544. Its totient is φ = 64512.

The previous prime is 172717. The next prime is 172721. The reversal of 172720 is 27271.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (172721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1297 + ... + 1423.

2¹⁷²⁷²⁰ is an apocalyptic number.

172720 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 172720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (214272).

172720 is an abundant number, since it is smaller than the sum of its proper divisors (255824).

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

172720 is a wasteful number, since it uses less digits than its factorization.

172720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 19.

The square root of 172720 is about 415.5959576319. The cubic root of 172720 is about 55.6904691417.

Adding to 172720 its reverse (27271), we get a palindrome (199991).

The spelling of 172720 in words is "one hundred seventy-two thousand, seven hundred twenty", and thus it is an iban number.