28061021791 has 16 divisors (see below), whose sum is σ = 30920663808. Its totient is φ = 25464028920.

The previous prime is 28061021783. The next prime is 28061021827. The reversal of 28061021791 is 19712016082.

It is not a de Polignac number, because 28061021791 - 2³ = 28061021783 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 28061021791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28061024791) 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 15 ways as a sum of consecutive naturals, for example, 730630 + ... + 768076.

It is an arithmetic number, because the mean of its divisors is an integer number (1932541488).

Almost surely, 2^28061021791 is an apocalyptic number.

28061021791 is a deficient number, since it is larger than the sum of its proper divisors (2859642017).

28061021791 is an equidigital number, since it uses as much as digits as its factorization.

28061021791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38043 (or 38021 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 37.

The spelling of 28061021791 in words is "twenty-eight billion, sixty-one million, twenty-one thousand, seven hundred ninety-one".