28559509931 has 4 divisors (see below), whose sum is σ = 28561375200. Its totient is φ = 28557644664.

The previous prime is 28559509921. The next prime is 28559509961. The reversal of 28559509931 is 13990595582.

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-28559509931 is a prime.

It is a super-2 number, since 2×28559509931² (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 (28559509921) 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, 909476 + ... + 940353.

It is an arithmetic number, because the mean of its divisors is an integer number (7140343800).

Almost surely, 2^28559509931 is an apocalyptic number.

28559509931 is a deficient number, since it is larger than the sum of its proper divisors (1865269).

28559509931 is a wasteful number, since it uses less digits than its factorization.

28559509931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1865268.

The product of its (nonzero) digits is 4374000, while the sum is 56.

The spelling of 28559509931 in words is "twenty-eight billion, five hundred fifty-nine million, five hundred nine thousand, nine hundred thirty-one".