805861221 has 16 divisors (see below), whose sum is σ = 1203843648. Its totient is φ = 475200000.

The previous prime is 805861219. The next prime is 805861247. The reversal of 805861221 is 122168508.

It is not a de Polignac number, because 805861221 - 2¹ = 805861219 is a prime.

It is a super-2 number, since 2×805861221² = 1298824615023221682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (805861211) 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, 328780 + ... + 331221.

It is an arithmetic number, because the mean of its divisors is an integer number (75240228).

Almost surely, 2^805861221 is an apocalyptic number.

It is an amenable number.

805861221 is a deficient number, since it is larger than the sum of its proper divisors (397982427).

805861221 is a wasteful number, since it uses less digits than its factorization.

805861221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660052.

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 805861221 is about 28387.6948870457. The cubic root of 805861221 is about 930.5793672857.

The spelling of 805861221 in words is "eight hundred five million, eight hundred sixty-one thousand, two hundred twenty-one".