28691428 has 12 divisors (see below), whose sum is σ = 51567292. Its totient is φ = 13957920.

The previous prime is 28691417. The next prime is 28691483. The reversal of 28691428 is 82419682.

It can be written as a sum of positive squares in 2 ways, for example, as 24920064 + 3771364 = 4992^2 + 1942^2 .

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96783 + ... + 97078.

Almost surely, 2^28691428 is an apocalyptic number.

It is an amenable number.

28691428 is a deficient number, since it is larger than the sum of its proper divisors (22875864).

28691428 is a wasteful number, since it uses less digits than its factorization.

28691428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193902 (or 193900 counting only the distinct ones).

The product of its digits is 55296, while the sum is 40.

The square root of 28691428 is about 5356.4379955340. The cubic root of 28691428 is about 306.1381038939.

The spelling of 28691428 in words is "twenty-eight million, six hundred ninety-one thousand, four hundred twenty-eight".