28778381231 has 8 divisors (see below), whose sum is σ = 28816158720. Its totient is φ = 28740630168.

The previous prime is 28778381173. The next prime is 28778381239. The reversal of 28778381231 is 13218387782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28778381231 - 2¹⁰ = 28778380207 is a prime.

It is a super-2 number, since 2×28778381231² (a number of 22 digits) contains 22 as substring.

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 28778381231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28778381239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2997020 + ... + 3006606.

It is an arithmetic number, because the mean of its divisors is an integer number (3602019840).

Almost surely, 2^28778381231 is an apocalyptic number.

28778381231 is a deficient number, since it is larger than the sum of its proper divisors (37777489).

28778381231 is a wasteful number, since it uses less digits than its factorization.

28778381231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13213.

The product of its digits is 903168, while the sum is 50.

The spelling of 28778381231 in words is "twenty-eight billion, seven hundred seventy-eight million, three hundred eighty-one thousand, two hundred thirty-one".