12690397 has 4 divisors (see below), whose sum is σ = 12699036. Its totient is φ = 12681760.

The previous prime is 12690389. The next prime is 12690401. The reversal of 12690397 is 79309621.

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: 79309621 = 41 ⋅1934381.

It can be written as a sum of positive squares in 2 ways, for example, as 9084196 + 3606201 = 3014^2 + 1899^2 .

It is a cyclic number.

It is not a de Polignac number, because 12690397 - 2³ = 12690389 is a prime.

It is a super-2 number, since 2×12690397² = 322092352035218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12690697) 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, 1504 + ... + 5257.

It is an arithmetic number, because the mean of its divisors is an integer number (3174759).

Almost surely, 2^12690397 is an apocalyptic number.

It is an amenable number.

12690397 is a deficient number, since it is larger than the sum of its proper divisors (8639).

12690397 is an equidigital number, since it uses as much as digits as its factorization.

12690397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8638.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 12690397 is about 3562.3583480610. The cubic root of 12690397 is about 233.2518352567.

The spelling of 12690397 in words is "twelve million, six hundred ninety thousand, three hundred ninety-seven".