8491021 has 8 divisors (see below), whose sum is σ = 10586304. Its totient is φ = 6616320.

The previous prime is 8491001. The next prime is 8491033. The reversal of 8491021 is 1201948.

It is a happy number.

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 8491021 - 2⁷ = 8490893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8491001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55060 + ... + 55213.

It is an arithmetic number, because the mean of its divisors is an integer number (1323288).

Almost surely, 2^8491021 is an apocalyptic number.

It is an amenable number.

8491021 is a deficient number, since it is larger than the sum of its proper divisors (2095283).

8491021 is a wasteful number, since it uses less digits than its factorization.

8491021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110291.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 8491021 is about 2913.9356547460. The cubic root of 8491021 is about 204.0108686379.

Adding to 8491021 its reverse (1201948), we get a palindrome (9692969).

The spelling of 8491021 in words is "eight million, four hundred ninety-one thousand, twenty-one".