28321509959 has 4 divisors (see below), whose sum is σ = 28324676640. Its totient is φ = 28318343280.

The previous prime is 28321509943. The next prime is 28321509971. The reversal of 28321509959 is 95990512382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95990512382 = 2 ⋅47995256191.

It is a cyclic number.

It is not a de Polignac number, because 28321509959 - 2⁴ = 28321509943 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28321509959.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28321509919) 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, 1569887 + ... + 1587824.

It is an arithmetic number, because the mean of its divisors is an integer number (7081169160).

Almost surely, 2^28321509959 is an apocalyptic number.

28321509959 is a deficient number, since it is larger than the sum of its proper divisors (3166681).

28321509959 is an equidigital number, since it uses as much as digits as its factorization.

28321509959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3166680.

The product of its (nonzero) digits is 1749600, while the sum is 53.

The spelling of 28321509959 in words is "twenty-eight billion, three hundred twenty-one million, five hundred nine thousand, nine hundred fifty-nine".