28493309 has 16 divisors (see below), whose sum is σ = 33546240. Its totient is φ = 23950080.

The previous prime is 28493303. The next prime is 28493321. The reversal of 28493309 is 90339482.

It is a cyclic number.

It is not a de Polignac number, because 28493309 - 2⁸ = 28493053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28493303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4772 + ... + 8930.

It is an arithmetic number, because the mean of its divisors is an integer number (2096640).

Almost surely, 2^28493309 is an apocalyptic number.

It is an amenable number.

28493309 is a deficient number, since it is larger than the sum of its proper divisors (5052931).

28493309 is a wasteful number, since it uses less digits than its factorization.

28493309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4220.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 28493309 is about 5337.9124196637. The cubic root of 28493309 is about 305.4318311993.

The spelling of 28493309 in words is "twenty-eight million, four hundred ninety-three thousand, three hundred nine".