820340 has 12 divisors (see below), whose sum is σ = 1722756. Its totient is φ = 328128.

The previous prime is 820333. The next prime is 820343. The reversal of 820340 is 43028.

It can be written as a sum of positive squares in 2 ways, for example, as 465124 + 355216 = 682^2 + 596^2 .

It is a nialpdrome in base 7.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820343) by changing a digit.

820340 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 3 ways as a sum of consecutive naturals, for example, 20489 + ... + 20528.

It is an arithmetic number, because the mean of its divisors is an integer number (143563).

2⁸²⁰³⁴⁰ is an apocalyptic number.

It is an amenable number.

820340 is an abundant number, since it is smaller than the sum of its proper divisors (902416).

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

820340 is a wasteful number, since it uses less digits than its factorization.

820340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41026 (or 41024 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 820340 is about 905.7262279519. The cubic root of 820340 is about 93.6119508933.

Adding to 820340 its reverse (43028), we get a palindrome (863368).

The spelling of 820340 in words is "eight hundred twenty thousand, three hundred forty".