8157691 has 4 divisors (see below), whose sum is σ = 8164800. Its totient is φ = 8150584.

The previous prime is 8157683. The next prime is 8157701. The reversal of 8157691 is 1967518.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 8157691 - 2³ = 8157683 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8157691.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8157641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1396 + ... + 4273.

It is an arithmetic number, because the mean of its divisors is an integer number (2041200).

Almost surely, 2^8157691 is an apocalyptic number.

8157691 is a deficient number, since it is larger than the sum of its proper divisors (7109).

8157691 is a wasteful number, since it uses less digits than its factorization.

8157691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7108.

The product of its digits is 15120, while the sum is 37.

The square root of 8157691 is about 2856.1671869833. The cubic root of 8157691 is about 201.3055508082.

The spelling of 8157691 in words is "eight million, one hundred fifty-seven thousand, six hundred ninety-one".