172420 has 24 divisors (see below), whose sum is σ = 373464. Its totient is φ = 66816.

The previous prime is 172411. The next prime is 172421. The reversal of 172420 is 24271.

It can be written as a sum of positive squares in 4 ways, for example, as 24964 + 147456 = 158^2 + 384^2 .

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 172394 and 172403.

It is not an unprimeable number, because it can be changed into a prime (172421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 624 + ... + 856.

It is an arithmetic number, because the mean of its divisors is an integer number (15561).

2¹⁷²⁴²⁰ is an apocalyptic number.

172420 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 172420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (186732).

172420 is an abundant number, since it is smaller than the sum of its proper divisors (201044).

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

172420 is a wasteful number, since it uses less digits than its factorization.

172420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 172420 is about 415.2348732946. The cubic root of 172420 is about 55.6582072476.

Adding to 172420 its reverse (24271), we get a palindrome (196691).

The spelling of 172420 in words is "one hundred seventy-two thousand, four hundred twenty", and thus it is an iban number.