8421591 has 4 divisors (see below), whose sum is σ = 11228792. Its totient is φ = 5614392.

The previous prime is 8421587. The next prime is 8421619. The reversal of 8421591 is 1951248.

It is a happy number.

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

It is not a de Polignac number, because 8421591 - 2² = 8421587 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 (8421191) 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, 1403596 + ... + 1403601.

It is an arithmetic number, because the mean of its divisors is an integer number (2807198).

Almost surely, 2^8421591 is an apocalyptic number.

8421591 is a deficient number, since it is larger than the sum of its proper divisors (2807201).

8421591 is a wasteful number, since it uses less digits than its factorization.

8421591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2807200.

The product of its digits is 2880, while the sum is 30.

The square root of 8421591 is about 2901.9977601645. The cubic root of 8421591 is about 203.4532891278.

The spelling of 8421591 in words is "eight million, four hundred twenty-one thousand, five hundred ninety-one".