172020 has 48 divisors (see below), whose sum is σ = 499968. Its totient is φ = 44160.

The previous prime is 172009. The next prime is 172021. The reversal of 172020 is 20271.

172020 = T₁₉₁ + T₁₉₂ + ... + T₁₉₉.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 171987 and 172005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172021) by changing a digit.

172020 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 15 ways as a sum of consecutive naturals, for example, 2790 + ... + 2850.

It is an arithmetic number, because the mean of its divisors is an integer number (10416).

2¹⁷²⁰²⁰ is an apocalyptic number.

172020 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 172020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249984).

172020 is an abundant number, since it is smaller than the sum of its proper divisors (327948).

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

172020 is a wasteful number, since it uses less digits than its factorization.

172020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 28, while the sum is 12.

The square root of 172020 is about 414.7529385068. The cubic root of 172020 is about 55.6151331234.

Adding to 172020 its reverse (20271), we get a palindrome (192291).

The spelling of 172020 in words is "one hundred seventy-two thousand, twenty", and thus it is an iban number.