12781816 has 16 divisors (see below), whose sum is σ = 24129000. Its totient is φ = 6347424.

The previous prime is 12781799. The next prime is 12781817. The reversal of 12781816 is 61818721.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12781817) 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, 4170 + ... + 6553.

Almost surely, 2^12781816 is an apocalyptic number.

It is an amenable number.

12781816 is a deficient number, since it is larger than the sum of its proper divisors (11347184).

12781816 is a wasteful number, since it uses less digits than its factorization.

12781816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10878 (or 10874 counting only the distinct ones).

The product of its digits is 5376, while the sum is 34.

The square root of 12781816 is about 3575.1665695461. The cubic root of 12781816 is about 233.8105950220.

The spelling of 12781816 in words is "twelve million, seven hundred eighty-one thousand, eight hundred sixteen".