28530399 has 4 divisors (see below), whose sum is σ = 38040536. Its totient is φ = 19020264.

The previous prime is 28530391. The next prime is 28530407. The reversal of 28530399 is 99303582.

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 (28530391) and next prime (28530407).

It is not a de Polignac number, because 28530399 - 2³ = 28530391 is a prime.

It is a super-3 number, since 3×28530399³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28530391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4755064 + ... + 4755069.

It is an arithmetic number, because the mean of its divisors is an integer number (9510134).

Almost surely, 2^28530399 is an apocalyptic number.

28530399 is a deficient number, since it is larger than the sum of its proper divisors (9510137).

28530399 is an equidigital number, since it uses as much as digits as its factorization.

28530399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9510136.

The product of its (nonzero) digits is 58320, while the sum is 39.

The square root of 28530399 is about 5341.3854944200. The cubic root of 28530399 is about 305.5643015360.

The spelling of 28530399 in words is "twenty-eight million, five hundred thirty thousand, three hundred ninety-nine".