8591021 has 4 divisors (see below), whose sum is σ = 9043200. Its totient is φ = 8138844.

The previous prime is 8590997. The next prime is 8591039. The reversal of 8591021 is 1201958.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1201958 = 2 ⋅600979.

It is a cyclic number.

It is not a de Polignac number, because 8591021 - 2⁶ = 8590957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8591041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226061 + ... + 226098.

It is an arithmetic number, because the mean of its divisors is an integer number (2260800).

Almost surely, 2^8591021 is an apocalyptic number.

It is an amenable number.

8591021 is a deficient number, since it is larger than the sum of its proper divisors (452179).

8591021 is a wasteful number, since it uses less digits than its factorization.

8591021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452178.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 8591021 is about 2931.0443531274. The cubic root of 8591021 is about 204.8086336311.

Adding to 8591021 its reverse (1201958), we get a palindrome (9792979).

The spelling of 8591021 in words is "eight million, five hundred ninety-one thousand, twenty-one".