28657399 has 4 divisors (see below), whose sum is σ = 28687536. Its totient is φ = 28627264.

The previous prime is 28657331. The next prime is 28657439. The reversal of 28657399 is 99375682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28657399 - 2¹⁷ = 28526327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28657309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13594 + ... + 15559.

It is an arithmetic number, because the mean of its divisors is an integer number (7171884).

Almost surely, 2^28657399 is an apocalyptic number.

28657399 is a deficient number, since it is larger than the sum of its proper divisors (30137).

28657399 is an equidigital number, since it uses as much as digits as its factorization.

28657399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30136.

The product of its digits is 816480, while the sum is 49.

The square root of 28657399 is about 5353.2605951887. The cubic root of 28657399 is about 306.0170259796.

The spelling of 28657399 in words is "twenty-eight million, six hundred fifty-seven thousand, three hundred ninety-nine".