12781866 has 16 divisors (see below), whose sum is σ = 26445600. Its totient is φ = 4113648.

The previous prime is 12781861. The next prime is 12781871. The reversal of 12781866 is 66818721.

It is an interprime number because it is at equal distance from previous prime (12781861) and next prime (12781871).

It is not an unprimeable number, because it can be changed into a prime (12781861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36556 + ... + 36903.

It is an arithmetic number, because the mean of its divisors is an integer number (1652850).

Almost surely, 2^12781866 is an apocalyptic number.

12781866 is an abundant number, since it is smaller than the sum of its proper divisors (13663734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12781866 is a wasteful number, since it uses less digits than its factorization.

12781866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73493.

The product of its digits is 32256, while the sum is 39.

The square root of 12781866 is about 3575.1735622204. The cubic root of 12781866 is about 233.8108998956.

The spelling of 12781866 in words is "twelve million, seven hundred eighty-one thousand, eight hundred sixty-six".