813965 has 8 divisors (see below), whose sum is σ = 983448. Its totient is φ = 646720.

The previous prime is 813961. The next prime is 813971. The reversal of 813965 is 569318.

It can be written as a sum of positive squares in 4 ways, for example, as 276676 + 537289 = 526^2 + 733^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 813965 - 2² = 813961 is a prime.

It is a Duffinian number.

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 813965.

It is not an unprimeable number, because it can be changed into a prime (813961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395 + ... + 1335.

It is an arithmetic number, because the mean of its divisors is an integer number (122931).

2⁸¹³⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

813965 is a deficient number, since it is larger than the sum of its proper divisors (169483).

813965 is a wasteful number, since it uses less digits than its factorization.

813965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1119.

The product of its digits is 6480, while the sum is 32.

The square root of 813965 is about 902.2000886721. The cubic root of 813965 is about 93.3688286194.

The spelling of 813965 in words is "eight hundred thirteen thousand, nine hundred sixty-five".