28158520105 has 4 divisors (see below), whose sum is σ = 33790224132. Its totient is φ = 22526816080.

The previous prime is 28158520097. The next prime is 28158520111. The reversal of 28158520105 is 50102585182.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5242918464 + 22915601641 = 72408^2 + 151379^2 .

It is not a de Polignac number, because 28158520105 - 2³ = 28158520097 is a prime.

It is a super-4 number, since 4×28158520105⁴ (a number of 43 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2815852006 + ... + 2815852015.

It is an arithmetic number, because the mean of its divisors is an integer number (8447556033).

Almost surely, 2^28158520105 is an apocalyptic number.

It is an amenable number.

28158520105 is a deficient number, since it is larger than the sum of its proper divisors (5631704027).

28158520105 is an equidigital number, since it uses as much as digits as its factorization.

28158520105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5631704026.

The product of its (nonzero) digits is 32000, while the sum is 37.

The spelling of 28158520105 in words is "twenty-eight billion, one hundred fifty-eight million, five hundred twenty thousand, one hundred five".