813643 has 4 divisors (see below), whose sum is σ = 819720. Its totient is φ = 807568.

The previous prime is 813623. The next prime is 813647. The reversal of 813643 is 346318.

813643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 813643 - 2¹³ = 805451 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 8³ + 1 + 6⁷ + 3⁶ + 4⁵ + 3¹² .

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (813647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2833 + ... + 3106.

It is an arithmetic number, because the mean of its divisors is an integer number (204930).

2⁸¹³⁶⁴³ is an apocalyptic number.

813643 is a deficient number, since it is larger than the sum of its proper divisors (6077).

813643 is a wasteful number, since it uses less digits than its factorization.

813643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6076.

The product of its digits is 1728, while the sum is 25.

The square root of 813643 is about 902.0216183662. The cubic root of 813643 is about 93.3565149334.

The spelling of 813643 in words is "eight hundred thirteen thousand, six hundred forty-three".