8131997 has 2 divisors, whose sum is σ = 8131998. Its totient is φ = 8131996.

The previous prime is 8131993. The next prime is 8131999. The reversal of 8131997 is 7991318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7695076 + 436921 = 2774^2 + 661^2 .

It is a cyclic number.

It is not a de Polignac number, because 8131997 - 2² = 8131993 is a prime.

It is a super-2 number, since 2×8131997² = 132258750416018, which contains 22 as substring.

Together with 8131999, it forms a pair of twin primes.

It is a Chen prime.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 8131997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8131993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4065998 + 4065999.

It is an arithmetic number, because the mean of its divisors is an integer number (4065999).

Almost surely, 2^8131997 is an apocalyptic number.

It is an amenable number.

8131997 is a deficient number, since it is larger than the sum of its proper divisors (1).

8131997 is an equidigital number, since it uses as much as digits as its factorization.

8131997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 38.

The square root of 8131997 is about 2851.6656536137. The cubic root of 8131997 is about 201.0939801269.

The spelling of 8131997 in words is "eight million, one hundred thirty-one thousand, nine hundred ninety-seven".