28081645169 has 4 divisors (see below), whose sum is σ = 28171940160. Its totient is φ = 27991350180.

The previous prime is 28081645153. The next prime is 28081645181. The reversal of 28081645169 is 96154618082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28081645169 - 2⁴ = 28081645153 is a prime.

It is a super-2 number, since 2×28081645169² (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 (28081645129) 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, 45147029 + ... + 45147650.

It is an arithmetic number, because the mean of its divisors is an integer number (7042985040).

Almost surely, 2^28081645169 is an apocalyptic number.

It is an amenable number.

28081645169 is a deficient number, since it is larger than the sum of its proper divisors (90294991).

28081645169 is an equidigital number, since it uses as much as digits as its factorization.

28081645169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90294990.

The product of its (nonzero) digits is 829440, while the sum is 50.

The spelling of 28081645169 in words is "twenty-eight billion, eighty-one million, six hundred forty-five thousand, one hundred sixty-nine".