28729873 has 4 divisors (see below), whose sum is σ = 29216880. Its totient is φ = 28242868.

The previous prime is 28729853. The next prime is 28729903. The reversal of 28729873 is 37892782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 37892782 = 2 ⋅18946391.

It is a cyclic number.

It is not a de Polignac number, because 28729873 - 2²¹ = 26632721 is a prime.

It is a super-2 number, since 2×28729873² = 1650811205192258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28729853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243415 + ... + 243532.

It is an arithmetic number, because the mean of its divisors is an integer number (7304220).

Almost surely, 2^28729873 is an apocalyptic number.

It is an amenable number.

28729873 is a deficient number, since it is larger than the sum of its proper divisors (487007).

28729873 is an equidigital number, since it uses as much as digits as its factorization.

28729873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487006.

The product of its digits is 338688, while the sum is 46.

The square root of 28729873 is about 5360.0254663574. The cubic root of 28729873 is about 306.2747791695.

The spelling of 28729873 in words is "twenty-eight million, seven hundred twenty-nine thousand, eight hundred seventy-three".