12639428 has 12 divisors (see below), whose sum is σ = 22589952. Its totient is φ = 6185160.

The previous prime is 12639379. The next prime is 12639433. The reversal of 12639428 is 82493621.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33428 + ... + 33803.

It is an arithmetic number, because the mean of its divisors is an integer number (1882496).

Almost surely, 2^12639428 is an apocalyptic number.

It is an amenable number.

12639428 is a deficient number, since it is larger than the sum of its proper divisors (9950524).

12639428 is a wasteful number, since it uses less digits than its factorization.

12639428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67282 (or 67280 counting only the distinct ones).

The product of its digits is 20736, while the sum is 35.

The square root of 12639428 is about 3555.1973222312. The cubic root of 12639428 is about 232.9391430519.

The spelling of 12639428 in words is "twelve million, six hundred thirty-nine thousand, four hundred twenty-eight".