12157997 has 2 divisors, whose sum is σ = 12157998. Its totient is φ = 12157996.

The previous prime is 12157987. The next prime is 12158011. The reversal of 12157997 is 79975121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11115556 + 1042441 = 3334^2 + 1021^2 .

It is an emirp because it is prime and its reverse (79975121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12157997 - 2⁶ = 12157933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12157927) 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 as a sum of consecutive naturals, namely, 6078998 + 6078999.

It is an arithmetic number, because the mean of its divisors is an integer number (6078999).

Almost surely, 2^12157997 is an apocalyptic number.

It is an amenable number.

12157997 is a deficient number, since it is larger than the sum of its proper divisors (1).

12157997 is an equidigital number, since it uses as much as digits as its factorization.

12157997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39690, while the sum is 41.

The square root of 12157997 is about 3486.8319431828. The cubic root of 12157997 is about 229.9432563232.

The spelling of 12157997 in words is "twelve million, one hundred fifty-seven thousand, nine hundred ninety-seven".