12905805 has 64 divisors (see below), whose sum is σ = 24634368. Its totient is φ = 5698560.

The previous prime is 12905803. The next prime is 12905861. The reversal of 12905805 is 50850921.

It is not a de Polignac number, because 12905805 - 2¹ = 12905803 is a prime.

12905805 is a modest number, since divided by 5805 gives 1290 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12905803) 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 63 ways as a sum of consecutive naturals, for example, 120562 + ... + 120668.

It is an arithmetic number, because the mean of its divisors is an integer number (384912).

Almost surely, 2^12905805 is an apocalyptic number.

12905805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12905805 is a deficient number, since it is larger than the sum of its proper divisors (11728563).

12905805 is a wasteful number, since it uses less digits than its factorization.

12905805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186.

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 12905805 is about 3592.4650311450. The cubic root of 12905805 is about 234.5641839636.

Subtracting 12905805 from its reverse (50850921), we obtain a triangular number (37945116 = T₈₇₁₁).

The spelling of 12905805 in words is "twelve million, nine hundred five thousand, eight hundred five".