28188727231 has 16 divisors (see below), whose sum is σ = 32329670400. Its totient is φ = 24076398528.

The previous prime is 28188727223. The next prime is 28188727249. The reversal of 28188727231 is 13272788182.

It is a happy number.

It is not a de Polignac number, because 28188727231 - 2³ = 28188727223 is a prime.

It is a super-2 number, since 2×28188727231² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28188727631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3415596 + ... + 3423838.

It is an arithmetic number, because the mean of its divisors is an integer number (2020604400).

Almost surely, 2^28188727231 is an apocalyptic number.

28188727231 is a deficient number, since it is larger than the sum of its proper divisors (4140943169).

28188727231 is a wasteful number, since it uses less digits than its factorization.

28188727231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9918.

The product of its digits is 602112, while the sum is 49.

The spelling of 28188727231 in words is "twenty-eight billion, one hundred eighty-eight million, seven hundred twenty-seven thousand, two hundred thirty-one".