12905 has 8 divisors (see below), whose sum is σ = 16200. Its totient is φ = 9856.

The previous prime is 12899. The next prime is 12907. The reversal of 12905 is 50921.

12905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 361 + 12544 = 19^2 + 112^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12905 - 2⁴ = 12889 is a prime.

It is an alternating number because its digits alternate between odd and even.

12905 is an undulating number in base 12.

It is a plaindrome in base 14.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (12907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101 + ... + 189.

It is an arithmetic number, because the mean of its divisors is an integer number (2025).

2¹²⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

12905 is a deficient number, since it is larger than the sum of its proper divisors (3295).

12905 is an equidigital number, since it uses as much as digits as its factorization.

12905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 12905 is about 113.6001760562. The cubic root of 12905 is about 23.4559306879.

The spelling of 12905 in words is "twelve thousand, nine hundred five".