28328387 has 4 divisors (see below), whose sum is σ = 29560080. Its totient is φ = 27096696.

The previous prime is 28328381. The next prime is 28328393. The reversal of 28328387 is 78382382.

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

It is an interprime number because it is at equal distance from previous prime (28328381) and next prime (28328393).

It is a cyclic number.

It is not a de Polignac number, because 28328387 - 2⁶ = 28328323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28328381) 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, 615812 + ... + 615857.

It is an arithmetic number, because the mean of its divisors is an integer number (7390020).

Almost surely, 2^28328387 is an apocalyptic number.

28328387 is a deficient number, since it is larger than the sum of its proper divisors (1231693).

28328387 is a wasteful number, since it uses less digits than its factorization.

28328387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1231692.

The product of its digits is 129024, while the sum is 41.

The square root of 28328387 is about 5322.4418268310. The cubic root of 28328387 is about 304.8414010155.

The spelling of 28328387 in words is "twenty-eight million, three hundred twenty-eight thousand, three hundred eighty-seven".