8021605 has 8 divisors (see below), whose sum is σ = 9758232. Its totient is φ = 6329088.

The previous prime is 8021597. The next prime is 8021627. The reversal of 8021605 is 5061208.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 887364 + 7134241 = 942^2 + 2671^2 .

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 8021605 - 2³ = 8021597 is a prime.

It is a super-2 number, since 2×8021605² = 128692293552050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 10624 + ... + 11353.

It is an arithmetic number, because the mean of its divisors is an integer number (1219779).

Almost surely, 2^8021605 is an apocalyptic number.

It is an amenable number.

8021605 is a deficient number, since it is larger than the sum of its proper divisors (1736627).

8021605 is a wasteful number, since it uses less digits than its factorization.

8021605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22055.

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

The square root of 8021605 is about 2832.2438101265. The cubic root of 8021605 is about 200.1798798344.

It can be divided in two parts, 802 and 1605, that multiplied together give a triangular number (1287210 = T₁₆₀₄).

The spelling of 8021605 in words is "eight million, twenty-one thousand, six hundred five".