28721497289 has 4 divisors (see below), whose sum is σ = 29332593024. Its totient is φ = 28110401556.

The previous prime is 28721497283. The next prime is 28721497309. The reversal of 28721497289 is 98279412782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98279412782 = 2 ⋅49139706391.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28721497289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28721497283) 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, 305547797 + ... + 305547890.

It is an arithmetic number, because the mean of its divisors is an integer number (7333148256).

Almost surely, 2^28721497289 is an apocalyptic number.

It is an amenable number.

28721497289 is a deficient number, since it is larger than the sum of its proper divisors (611095735).

28721497289 is an equidigital number, since it uses as much as digits as its factorization.

28721497289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611095734.

The product of its digits is 8128512, while the sum is 59.

The spelling of 28721497289 in words is "twenty-eight billion, seven hundred twenty-one million, four hundred ninety-seven thousand, two hundred eighty-nine".