812021 has 8 divisors (see below), whose sum is σ = 933504. Its totient is φ = 691920.

The previous prime is 812011. The next prime is 812033. The reversal of 812021 is 120218.

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

It is a cyclic number.

It is not a de Polignac number, because 812021 - 2⁶ = 811957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 811987 and 812005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1991 + ... + 2363.

It is an arithmetic number, because the mean of its divisors is an integer number (116688).

2⁸¹²⁰²¹ is an apocalyptic number.

It is an amenable number.

812021 is a deficient number, since it is larger than the sum of its proper divisors (121483).

812021 is a wasteful number, since it uses less digits than its factorization.

812021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 812021 is about 901.1220783002. The cubic root of 812021 is about 93.2944381584.

Adding to 812021 its reverse (120218), we get a palindrome (932239).

The spelling of 812021 in words is "eight hundred twelve thousand, twenty-one".