12821878 has 4 divisors (see below), whose sum is σ = 19232820. Its totient is φ = 6410938.

The previous prime is 12821843. The next prime is 12821891. The reversal of 12821878 is 87812821.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 3205468 + ... + 3205471.

It is an arithmetic number, because the mean of its divisors is an integer number (4808205).

Almost surely, 2^12821878 is an apocalyptic number.

12821878 is a deficient number, since it is larger than the sum of its proper divisors (6410942).

12821878 is an equidigital number, since it uses as much as digits as its factorization.

12821878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6410941.

The product of its digits is 14336, while the sum is 37.

The square root of 12821878 is about 3580.7650020631. The cubic root of 12821878 is about 234.0546174892.

It can be divided in two parts, 1282 and 1878, that added together give a triangular number (3160 = T₇₉).

The spelling of 12821878 in words is "twelve million, eight hundred twenty-one thousand, eight hundred seventy-eight".