28686404 has 12 divisors (see below), whose sum is σ = 50347500. Its totient is φ = 14301408.

The previous prime is 28686367. The next prime is 28686407. The reversal of 28686404 is 40468682.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 25482304 + 3204100 = 5048^2 + 1790^2 .

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (28686407) 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, 8879 + ... + 11670.

It is an arithmetic number, because the mean of its divisors is an integer number (4195625).

Almost surely, 2^28686404 is an apocalyptic number.

It is an amenable number.

28686404 is a deficient number, since it is larger than the sum of its proper divisors (21661096).

28686404 is a wasteful number, since it uses less digits than its factorization.

28686404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20902 (or 20900 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 38.

The square root of 28686404 is about 5355.9690066318. The cubic root of 28686404 is about 306.1202341244.

The spelling of 28686404 in words is "twenty-eight million, six hundred eighty-six thousand, four hundred four".