8391551 has 4 divisors (see below), whose sum is σ = 9590352. Its totient is φ = 7192752.

The previous prime is 8391533. The next prime is 8391553. The reversal of 8391551 is 1551938.

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

It is a de Polignac number, because none of the positive numbers 2^k-8391551 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 (8391553) 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, 599390 + ... + 599403.

It is an arithmetic number, because the mean of its divisors is an integer number (2397588).

Almost surely, 2^8391551 is an apocalyptic number.

8391551 is a deficient number, since it is larger than the sum of its proper divisors (1198801).

8391551 is a wasteful number, since it uses less digits than its factorization.

8391551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198800.

The product of its digits is 5400, while the sum is 32.

The square root of 8391551 is about 2896.8173915523. The cubic root of 8391551 is about 203.2110934770.

The spelling of 8391551 in words is "eight million, three hundred ninety-one thousand, five hundred fifty-one".