12291397 has 4 divisors (see below), whose sum is σ = 12413196. Its totient is φ = 12169600.

The previous prime is 12291379. The next prime is 12291403. The reversal of 12291397 is 79319221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79319221 = 47 ⋅1687643.

It can be written as a sum of positive squares in 2 ways, for example, as 10074276 + 2217121 = 3174^2 + 1489^2 .

It is a cyclic number.

It is not a de Polignac number, because 12291397 - 2¹⁹ = 11767109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12291497) 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 in 3 ways as a sum of consecutive naturals, for example, 60748 + ... + 60949.

It is an arithmetic number, because the mean of its divisors is an integer number (3103299).

Almost surely, 2^12291397 is an apocalyptic number.

It is an amenable number.

12291397 is a deficient number, since it is larger than the sum of its proper divisors (121799).

12291397 is a wasteful number, since it uses less digits than its factorization.

12291397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121798.

The product of its digits is 6804, while the sum is 34.

The square root of 12291397 is about 3505.9088693233. The cubic root of 12291397 is about 230.7811937075.

It can be divided in two parts, 122 and 91397, that added together give a palindrome (91519).

The spelling of 12291397 in words is "twelve million, two hundred ninety-one thousand, three hundred ninety-seven".