8221705 has 4 divisors (see below), whose sum is σ = 9866052. Its totient is φ = 6577360.

The previous prime is 8221669. The next prime is 8221721. The reversal of 8221705 is 5071228.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5626384 + 2595321 = 2372^2 + 1611^2 .

It is not a de Polignac number, because 8221705 - 2¹¹ = 8219657 is a prime.

It is a Duffinian number.

8221705 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 8221705.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 822166 + ... + 822175.

It is an arithmetic number, because the mean of its divisors is an integer number (2466513).

Almost surely, 2^8221705 is an apocalyptic number.

It is an amenable number.

8221705 is a deficient number, since it is larger than the sum of its proper divisors (1644347).

8221705 is a wasteful number, since it uses less digits than its factorization.

8221705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644346.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 8221705 is about 2867.3515654694. The cubic root of 8221705 is about 201.8307326249.

The spelling of 8221705 in words is "eight million, two hundred twenty-one thousand, seven hundred five".