28384531 has 4 divisors (see below), whose sum is σ = 32439472. Its totient is φ = 24329592.

The previous prime is 28384529. The next prime is 28384549. The reversal of 28384531 is 13548382.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13548382 = 2 ⋅6774191.

It is not a de Polignac number, because 28384531 - 2¹ = 28384529 is a prime.

It is a super-2 number, since 2×28384531² = 1611363200179922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28384571) 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, 2027460 + ... + 2027473.

It is an arithmetic number, because the mean of its divisors is an integer number (8109868).

Almost surely, 2^28384531 is an apocalyptic number.

28384531 is a deficient number, since it is larger than the sum of its proper divisors (4054941).

28384531 is an equidigital number, since it uses as much as digits as its factorization.

28384531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4054940.

The product of its digits is 23040, while the sum is 34.

The square root of 28384531 is about 5327.7134870411. The cubic root of 28384531 is about 305.0426564007.

The spelling of 28384531 in words is "twenty-eight million, three hundred eighty-four thousand, five hundred thirty-one".