8391973 has 4 divisors (see below), whose sum is σ = 8411788. Its totient is φ = 8372160.

The previous prime is 8391959. The next prime is 8391997. The reversal of 8391973 is 3791938.

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 3560769 + 4831204 = 1887^2 + 2198^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8391973 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 (8391073) 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 3 ways as a sum of consecutive naturals, for example, 9258 + ... + 10123.

It is an arithmetic number, because the mean of its divisors is an integer number (2102947).

Almost surely, 2^8391973 is an apocalyptic number.

It is an amenable number.

8391973 is a deficient number, since it is larger than the sum of its proper divisors (19815).

8391973 is a wasteful number, since it uses less digits than its factorization.

8391973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19814.

The product of its digits is 40824, while the sum is 40.

The square root of 8391973 is about 2896.8902291941. The cubic root of 8391973 is about 203.2144998256.

The spelling of 8391973 in words is "eight million, three hundred ninety-one thousand, nine hundred seventy-three".