28158112557 has 6 divisors (see below), whose sum is σ = 40672829262. Its totient is φ = 18772075032.

The previous prime is 28158112531. The next prime is 28158112559. The reversal of 28158112557 is 75521185182.

It is a happy number.

28158112557 is a `hidden beast` number, since 2 + 8 + 1 + 5 + 81 + 12 + 557 = 666.

It can be written as a sum of positive squares in only one way, i.e., 24756190281 + 3401922276 = 157341^2 + 58326^2 .

It is not a de Polignac number, because 28158112557 - 2¹⁰ = 28158111533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28158112559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1564339578 + ... + 1564339595.

It is an arithmetic number, because the mean of its divisors is an integer number (6778804877).

Almost surely, 2^28158112557 is an apocalyptic number.

It is an amenable number.

28158112557 is a deficient number, since it is larger than the sum of its proper divisors (12514716705).

28158112557 is a wasteful number, since it uses less digits than its factorization.

28158112557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3128679179 (or 3128679176 counting only the distinct ones).

The product of its digits is 224000, while the sum is 45.

It can be divided in two parts, 28158 and 112557, that added together give a triangular number (140715 = T₅₃₀).

The spelling of 28158112557 in words is "twenty-eight billion, one hundred fifty-eight million, one hundred twelve thousand, five hundred fifty-seven".