12691543 has 4 divisors (see below), whose sum is σ = 12784320. Its totient is φ = 12598768.

The previous prime is 12691541. The next prime is 12691583. The reversal of 12691543 is 34519621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34519621 = 191 ⋅180731.

It is a cyclic number.

It is not a de Polignac number, because 12691543 - 2¹ = 12691541 is a prime.

It is a super-2 number, since 2×12691543² = 322150527441698, 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 (12691541) 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 in 3 ways as a sum of consecutive naturals, for example, 46183 + ... + 46456.

It is an arithmetic number, because the mean of its divisors is an integer number (3196080).

Almost surely, 2^12691543 is an apocalyptic number.

12691543 is a deficient number, since it is larger than the sum of its proper divisors (92777).

12691543 is an equidigital number, since it uses as much as digits as its factorization.

12691543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92776.

The product of its digits is 6480, while the sum is 31.

The square root of 12691543 is about 3562.5191929308. The cubic root of 12691543 is about 233.2588562757.

The spelling of 12691543 in words is "twelve million, six hundred ninety-one thousand, five hundred forty-three".