28724689 has 8 divisors (see below), whose sum is σ = 32865920. Its totient is φ = 24592896.

The previous prime is 28724687. The next prime is 28724699. The reversal of 28724689 is 98642782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28724689 - 2¹ = 28724687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28724687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6292 + ... + 9850.

It is an arithmetic number, because the mean of its divisors is an integer number (4108240).

Almost surely, 2^28724689 is an apocalyptic number.

It is an amenable number.

28724689 is a deficient number, since it is larger than the sum of its proper divisors (4141231).

28724689 is a wasteful number, since it uses less digits than its factorization.

28724689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4719.

The product of its digits is 387072, while the sum is 46.

The square root of 28724689 is about 5359.5418647493. The cubic root of 28724689 is about 306.2563567194.

It can be divided in two parts, 287 and 24689, that added together give a triangular number (24976 = T₂₂₃).

The spelling of 28724689 in words is "twenty-eight million, seven hundred twenty-four thousand, six hundred eighty-nine".