28493728 has 12 divisors (see below), whose sum is σ = 56097090. Its totient is φ = 14246848.

The previous prime is 28493723. The next prime is 28493761. The reversal of 28493728 is 82739482.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 28430224 + 63504 = 5332^2 + 252^2 .

It is not an unprimeable number, because it can be changed into a prime (28493723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445183 + ... + 445246.

Almost surely, 2^28493728 is an apocalyptic number.

It is an amenable number.

28493728 is a deficient number, since it is larger than the sum of its proper divisors (27603362).

28493728 is an equidigital number, since it uses as much as digits as its factorization.

28493728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890439 (or 890431 counting only the distinct ones).

The product of its digits is 193536, while the sum is 43.

The square root of 28493728 is about 5337.9516670723. The cubic root of 28493728 is about 305.4333283380.

The spelling of 28493728 in words is "twenty-eight million, four hundred ninety-three thousand, seven hundred twenty-eight".