28057309 has 16 divisors (see below), whose sum is σ = 33649920. Its totient is φ = 22872960.

The previous prime is 28057307. The next prime is 28057343. The reversal of 28057309 is 90375082.

It is a cyclic number.

It is not a de Polignac number, because 28057309 - 2¹ = 28057307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28057307) 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, 36489 + ... + 37249.

It is an arithmetic number, because the mean of its divisors is an integer number (2103120).

Almost surely, 2^28057309 is an apocalyptic number.

It is an amenable number.

28057309 is a deficient number, since it is larger than the sum of its proper divisors (5592611).

28057309 is a wasteful number, since it uses less digits than its factorization.

28057309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 28057309 is about 5296.9150455713. The cubic root of 28057309 is about 303.8659272881.

The spelling of 28057309 in words is "twenty-eight million, fifty-seven thousand, three hundred nine".