197820 has 72 divisors (see below), whose sum is σ = 690144. Its totient is φ = 44928.

The previous prime is 197807. The next prime is 197831. The reversal of 197820 is 28791.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 197820.

It is an unprimeable number.

197820 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, 1182 + ... + 1338.

2¹⁹⁷⁸²⁰ is an apocalyptic number.

197820 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 197820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345072).

197820 is an abundant number, since it is smaller than the sum of its proper divisors (492324).

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

197820 is a wasteful number, since it uses less digits than its factorization.

197820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 174 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 197820 is about 444.7696032779. The cubic root of 197820 is about 58.2670994271.

The spelling of 197820 in words is "one hundred ninety-seven thousand, eight hundred twenty".