12918905 has 4 divisors (see below), whose sum is σ = 15502692. Its totient is φ = 10335120.

The previous prime is 12918901. The next prime is 12918907. The reversal of 12918905 is 50981921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50981921 = 19 ⋅2683259.

It can be written as a sum of positive squares in 2 ways, for example, as 2627641 + 10291264 = 1621^2 + 3208^2 .

It is not a de Polignac number, because 12918905 - 2² = 12918901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12918901) 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, 1291886 + ... + 1291895.

It is an arithmetic number, because the mean of its divisors is an integer number (3875673).

Almost surely, 2^12918905 is an apocalyptic number.

It is an amenable number.

12918905 is a deficient number, since it is larger than the sum of its proper divisors (2583787).

12918905 is an equidigital number, since it uses as much as digits as its factorization.

12918905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2583786.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 12918905 is about 3594.2878293203. The cubic root of 12918905 is about 234.6435216911.

The spelling of 12918905 in words is "twelve million, nine hundred eighteen thousand, nine hundred five".