172120 has 32 divisors (see below), whose sum is σ = 418320. Its totient is φ = 63360.

The previous prime is 172097. The next prime is 172127. The reversal of 172120 is 21271.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 172120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172127) by changing a digit.

172120 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355 + ... + 685.

2¹⁷²¹²⁰ is an apocalyptic number.

172120 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 172120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (209160).

172120 is an abundant number, since it is smaller than the sum of its proper divisors (246200).

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

172120 is a wasteful number, since it uses less digits than its factorization.

172120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 172120 is about 414.8734746884. The cubic root of 172120 is about 55.6259079093.

Adding to 172120 its reverse (21271), we get a palindrome (193391).

It can be divided in two parts, 172 and 120, that added together give a palindrome (292).

The spelling of 172120 in words is "one hundred seventy-two thousand, one hundred twenty", and thus it is an iban number.