170820 has 72 divisors (see below), whose sum is σ = 565656. Its totient is φ = 41472.

The previous prime is 170813. The next prime is 170827. The reversal of 170820 is 28071.

170820 = T₅₁ + T₅₂ + ... + T₁₀₄.

170820 is a nontrivial binomial coefficient, being equal to C(585, 2).

It is an interprime number because it is at equal distance from previous prime (170813) and next prime (170827).

It can be written as a sum of positive squares in 4 ways, for example, as 4356 + 166464 = 66^2 + 408^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 170793 and 170802.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 170820.

It is not an unprimeable number, because it can be changed into a prime (170827) by changing a digit.

170820 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 23 ways as a sum of consecutive naturals, for example, 2304 + ... + 2376.

2¹⁷⁰⁸²⁰ is an apocalyptic number.

170820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

170820 is the 584-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 170820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282828).

170820 is an abundant number, since it is smaller than the sum of its proper divisors (394836).

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

170820 is a wasteful number, since it uses less digits than its factorization.

170820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 170820 is about 413.3037623831. The cubic root of 170820 is about 55.4855087562.

Adding to 170820 its reverse (28071), we get a palindrome (198891).

It can be divided in two parts, 1708 and 20, that added together give a cube (1728 = 12³).

The spelling of 170820 in words is "one hundred seventy thousand, eight hundred twenty".