12811917 has 4 divisors (see below), whose sum is σ = 17082560. Its totient is φ = 8541276.

The previous prime is 12811907. The next prime is 12811927. The reversal of 12811917 is 71911821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71911821 = 3 ⋅23970607.

It is an interprime number because it is at equal distance from previous prime (12811907) and next prime (12811927).

It is not a de Polignac number, because 12811917 - 2⁶ = 12811853 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 (12811907) 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, 2135317 + ... + 2135322.

It is an arithmetic number, because the mean of its divisors is an integer number (4270640).

Almost surely, 2^12811917 is an apocalyptic number.

It is an amenable number.

12811917 is a deficient number, since it is larger than the sum of its proper divisors (4270643).

12811917 is an equidigital number, since it uses as much as digits as its factorization.

12811917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4270642.

The product of its digits is 1008, while the sum is 30.

The square root of 12811917 is about 3579.3738279202. The cubic root of 12811917 is about 233.9939913718.

The spelling of 12811917 in words is "twelve million, eight hundred eleven thousand, nine hundred seventeen".