820613 has 4 divisors (see below), whose sum is σ = 848940. Its totient is φ = 792288.

The previous prime is 820609. The next prime is 820619. The reversal of 820613 is 316028.

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

It can be written as a sum of positive squares in 2 ways, for example, as 232324 + 588289 = 482^2 + 767^2 .

It is a cyclic number.

It is not a de Polignac number, because 820613 - 2² = 820609 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820619) 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, 14120 + ... + 14177.

It is an arithmetic number, because the mean of its divisors is an integer number (212235).

2⁸²⁰⁶¹³ is an apocalyptic number.

It is an amenable number.

820613 is a deficient number, since it is larger than the sum of its proper divisors (28327).

820613 is a wasteful number, since it uses less digits than its factorization.

820613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28326.

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

The square root of 820613 is about 905.8769232076. The cubic root of 820613 is about 93.6223340792.

The spelling of 820613 in words is "eight hundred twenty thousand, six hundred thirteen".