8131691 has 2 divisors, whose sum is σ = 8131692. Its totient is φ = 8131690.

The previous prime is 8131681. The next prime is 8131693. The reversal of 8131691 is 1961318.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8131691 is a prime.

It is a super-2 number, since 2×8131691² = 132248797038962, which contains 22 as substring.

Together with 8131693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8131693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4065845 + 4065846.

It is an arithmetic number, because the mean of its divisors is an integer number (4065846).

Almost surely, 2^8131691 is an apocalyptic number.

8131691 is a deficient number, since it is larger than the sum of its proper divisors (1).

8131691 is an equidigital number, since it uses as much as digits as its factorization.

8131691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 29.

The square root of 8131691 is about 2851.6120002553. The cubic root of 8131691 is about 201.0914577645.

The spelling of 8131691 in words is "eight million, one hundred thirty-one thousand, six hundred ninety-one".