12784661 has 4 divisors (see below), whose sum is σ = 13096524. Its totient is φ = 12472800.

The previous prime is 12784643. The next prime is 12784687. The reversal of 12784661 is 16648721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16648721 = 83 ⋅200587.

It can be written as a sum of positive squares in 2 ways, for example, as 1768900 + 11015761 = 1330^2 + 3319^2 .

It is a cyclic number.

It is not a de Polignac number, because 12784661 - 2²² = 8590357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12784361) 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, 155870 + ... + 155951.

It is an arithmetic number, because the mean of its divisors is an integer number (3274131).

Almost surely, 2^12784661 is an apocalyptic number.

It is an amenable number.

12784661 is a deficient number, since it is larger than the sum of its proper divisors (311863).

12784661 is an equidigital number, since it uses as much as digits as its factorization.

12784661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311862.

The product of its digits is 16128, while the sum is 35.

The square root of 12784661 is about 3575.5644309675. The cubic root of 12784661 is about 233.8279410652.

The spelling of 12784661 in words is "twelve million, seven hundred eighty-four thousand, six hundred sixty-one".