28057728107 has 4 divisors (see below), whose sum is σ = 28098808920. Its totient is φ = 28016647296.

The previous prime is 28057728073. The next prime is 28057728109. The reversal of 28057728107 is 70182775082.

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

It is a cyclic number.

It is not a de Polignac number, because 28057728107 - 2¹⁴ = 28057711723 is a prime.

It is a super-2 number, since 2×28057728107² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28057728109) 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 3 ways as a sum of consecutive naturals, for example, 20539382 + ... + 20540747.

It is an arithmetic number, because the mean of its divisors is an integer number (7024702230).

Almost surely, 2^28057728107 is an apocalyptic number.

28057728107 is a deficient number, since it is larger than the sum of its proper divisors (41080813).

28057728107 is an equidigital number, since it uses as much as digits as its factorization.

28057728107 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41080812.

The product of its (nonzero) digits is 439040, while the sum is 47.

The spelling of 28057728107 in words is "twenty-eight billion, fifty-seven million, seven hundred twenty-eight thousand, one hundred seven".