12915691 has 4 divisors (see below), whose sum is σ = 12926752. Its totient is φ = 12904632.

The previous prime is 12915689. The next prime is 12915709. The reversal of 12915691 is 19651921.

It is a happy number.

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: 19651921 = 37 ⋅531133.

It is a cyclic number.

It is not a de Polignac number, because 12915691 - 2¹ = 12915689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12915391) 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, 3540 + ... + 6193.

It is an arithmetic number, because the mean of its divisors is an integer number (3231688).

Almost surely, 2^12915691 is an apocalyptic number.

12915691 is a deficient number, since it is larger than the sum of its proper divisors (11061).

12915691 is an equidigital number, since it uses as much as digits as its factorization.

12915691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11060.

The product of its digits is 4860, while the sum is 34.

The square root of 12915691 is about 3593.8407032032. The cubic root of 12915691 is about 234.6240616613.

The spelling of 12915691 in words is "twelve million, nine hundred fifteen thousand, six hundred ninety-one".