820380 has 72 divisors (see below), whose sum is σ = 2547216. Its totient is φ = 197120.

The previous prime is 820367. The next prime is 820399. The reversal of 820380 is 83028.

It is a Smith number, since the sum of its digits (21) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

820380 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, 7204 + ... + 7316.

It is an arithmetic number, because the mean of its divisors is an integer number (35378).

2⁸²⁰³⁸⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1273608).

820380 is an abundant number, since it is smaller than the sum of its proper divisors (1726836).

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

820380 is a wasteful number, since it uses less digits than its factorization.

820380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 820380 is about 905.7483094105. The cubic root of 820380 is about 93.6134723832.

The spelling of 820380 in words is "eight hundred twenty thousand, three hundred eighty".