805621 has 4 divisors (see below), whose sum is σ = 840672. Its totient is φ = 770572.

The previous prime is 805589. The next prime is 805633. The reversal of 805621 is 126508.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 805621 - 2⁵ = 805589 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 805592 and 805601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (805121) 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 3 ways as a sum of consecutive naturals, for example, 17491 + ... + 17536.

It is an arithmetic number, because the mean of its divisors is an integer number (210168).

2⁸⁰⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

805621 is a deficient number, since it is larger than the sum of its proper divisors (35051).

805621 is a wasteful number, since it uses less digits than its factorization.

805621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35050.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 805621 is about 897.5639253000. The cubic root of 805621 is about 93.0486891925.

The spelling of 805621 in words is "eight hundred five thousand, six hundred twenty-one".