28167915889 has 9 divisors (see below), whose sum is σ = 28375015617. Its totient is φ = 27962320464.

The previous prime is 28167915887. The next prime is 28167915907. The reversal of 28167915889 is 98851976182.

The square root of 28167915889 is 167833.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1666680625 + 26501235264 = 40825^2 + 162792^2 .

It is not a de Polignac number, because 28167915889 - 2¹ = 28167915887 is a prime.

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 28167915889.

It is not an unprimeable number, because it can be changed into a prime (28167915887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 26349247 + ... + 26350315.

It is an arithmetic number, because the mean of its divisors is an integer number (3152779513).

Almost surely, 2^28167915889 is an apocalyptic number.

28167915889 is the 167833-rd square number.

28167915889 is the 83917-th centered octagonal number.

It is an amenable number.

28167915889 is a deficient number, since it is larger than the sum of its proper divisors (207099728).

28167915889 is an frugal number, since it uses more digits than its factorization.

28167915889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2452 (or 1226 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 64.

Multiplying 28167915889 by its sum of digits (64), we get a square (1802746616896 = 1342664²).

The spelling of 28167915889 in words is "twenty-eight billion, one hundred sixty-seven million, nine hundred fifteen thousand, eight hundred eighty-nine".