12878661 has 4 divisors (see below), whose sum is σ = 17171552. Its totient is φ = 8585772.

The previous prime is 12878603. The next prime is 12878669. The reversal of 12878661 is 16687821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16687821 = 3 ⋅5562607.

It is not a de Polignac number, because 12878661 - 2¹⁰ = 12877637 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 (12878669) 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, 2146441 + ... + 2146446.

It is an arithmetic number, because the mean of its divisors is an integer number (4292888).

Almost surely, 2^12878661 is an apocalyptic number.

It is an amenable number.

12878661 is a deficient number, since it is larger than the sum of its proper divisors (4292891).

12878661 is an equidigital number, since it uses as much as digits as its factorization.

12878661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4292890.

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

The square root of 12878661 is about 3588.6851352550. The cubic root of 12878661 is about 234.3996203114.

The spelling of 12878661 in words is "twelve million, eight hundred seventy-eight thousand, six hundred sixty-one".