28663809 has 8 divisors (see below), whose sum is σ = 39451392. Its totient is φ = 18492720.

The previous prime is 28663787. The next prime is 28663813. The reversal of 28663809 is 90836682.

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

It is not a de Polignac number, because 28663809 - 2¹² = 28659713 is a prime.

It is a super-2 number, since 2×28663809² = 1643227892776962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28663849) 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, 154014 + ... + 154199.

It is an arithmetic number, because the mean of its divisors is an integer number (4931424).

It is a Proth number, since it is equal to 3499 ⋅ 2¹³ + 1 and 3499 < 2¹³.

Almost surely, 2^28663809 is an apocalyptic number.

It is an amenable number.

28663809 is a deficient number, since it is larger than the sum of its proper divisors (10787583).

28663809 is a wasteful number, since it uses less digits than its factorization.

28663809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308247.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 28663809 is about 5353.8592622519. The cubic root of 28663809 is about 306.0398405984.

The spelling of 28663809 in words is "twenty-eight million, six hundred sixty-three thousand, eight hundred nine".