8221691 has 4 divisors (see below), whose sum is σ = 8284584. Its totient is φ = 8158800.

The previous prime is 8221669. The next prime is 8221721. The reversal of 8221691 is 1961228.

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

It is a cyclic number.

It is not a de Polignac number, because 8221691 - 2⁶ = 8221627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8221621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31250 + ... + 31511.

It is an arithmetic number, because the mean of its divisors is an integer number (2071146).

Almost surely, 2^8221691 is an apocalyptic number.

8221691 is a deficient number, since it is larger than the sum of its proper divisors (62893).

8221691 is a wasteful number, since it uses less digits than its factorization.

8221691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62892.

The product of its digits is 1728, while the sum is 29.

The square root of 8221691 is about 2867.3491241912. The cubic root of 8221691 is about 201.8306180650.

The spelling of 8221691 in words is "eight million, two hundred twenty-one thousand, six hundred ninety-one".