28309258387 has 4 divisors (see below), whose sum is σ = 28589548176. Its totient is φ = 28028968600.

The previous prime is 28309258361. The next prime is 28309258391. The reversal of 28309258387 is 78385290382.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28309258387 is a prime.

It is a super-2 number, since 2×28309258387² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28309258357) 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, 140144743 + ... + 140144944.

It is an arithmetic number, because the mean of its divisors is an integer number (7147387044).

Almost surely, 2^28309258387 is an apocalyptic number.

28309258387 is a deficient number, since it is larger than the sum of its proper divisors (280289789).

28309258387 is a wasteful number, since it uses less digits than its factorization.

28309258387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280289788.

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 28309258387 in words is "twenty-eight billion, three hundred nine million, two hundred fifty-eight thousand, three hundred eighty-seven".