813021 has 16 divisors (see below), whose sum is σ = 1202688. Its totient is φ = 484400.

The previous prime is 813017. The next prime is 813023. The reversal of 813021 is 120318.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 813021 - 2² = 813017 is a prime.

It is a super-2 number, since 2×813021² = 1322006292882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2170 + ... + 2516.

It is an arithmetic number, because the mean of its divisors is an integer number (75168).

2⁸¹³⁰²¹ is an apocalyptic number.

It is an amenable number.

813021 is a deficient number, since it is larger than the sum of its proper divisors (389667).

813021 is a wasteful number, since it uses less digits than its factorization.

813021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 813021 is about 901.6767713543. The cubic root of 813021 is about 93.3327196672.

Adding to 813021 its reverse (120318), we get a palindrome (933339).

The spelling of 813021 in words is "eight hundred thirteen thousand, twenty-one".