813620 has 24 divisors (see below), whose sum is σ = 1809864. Its totient is φ = 306176.

The previous prime is 813613. The next prime is 813623. The reversal of 813620 is 26318.

It can be written as a sum of positive squares in 4 ways, for example, as 17956 + 795664 = 134^2 + 892^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 813592 and 813601.

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 813620.

It is not an unprimeable number, because it can be changed into a prime (813623) by changing a digit.

813620 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 7 ways as a sum of consecutive naturals, for example, 857 + ... + 1536.

It is an arithmetic number, because the mean of its divisors is an integer number (75411).

2⁸¹³⁶²⁰ is an apocalyptic number.

It is an amenable number.

813620 is an abundant number, since it is smaller than the sum of its proper divisors (996244).

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

813620 is a wasteful number, since it uses less digits than its factorization.

813620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2419 (or 2417 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 813620 is about 902.0088691360. The cubic root of 813620 is about 93.3556352601.

Adding to 813620 its reverse (26318), we get a palindrome (839938).

The spelling of 813620 in words is "eight hundred thirteen thousand, six hundred twenty".