12381997 has 4 divisors (see below), whose sum is σ = 12390300. Its totient is φ = 12373696.

The previous prime is 12381991. The next prime is 12382021. The reversal of 12381997 is 79918321.

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, and also an emirpimes, since its reverse is a distinct semiprime: 79918321 = 7 ⋅11416903.

It can be written as a sum of positive squares in 2 ways, for example, as 7946761 + 4435236 = 2819^2 + 2106^2 .

It is a cyclic number.

It is not a de Polignac number, because 12381997 - 2¹¹ = 12379949 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12381991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1228 + ... + 5125.

It is an arithmetic number, because the mean of its divisors is an integer number (3097575).

Almost surely, 2^12381997 is an apocalyptic number.

It is an amenable number.

12381997 is a deficient number, since it is larger than the sum of its proper divisors (8303).

12381997 is an equidigital number, since it uses as much as digits as its factorization.

12381997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8302.

The product of its digits is 27216, while the sum is 40.

The square root of 12381997 is about 3518.8061896047. The cubic root of 12381997 is about 231.3468362884.

The spelling of 12381997 in words is "twelve million, three hundred eighty-one thousand, nine hundred ninety-seven".