28168858181 has 2 divisors, whose sum is σ = 28168858182. Its totient is φ = 28168858180.

The previous prime is 28168858087. The next prime is 28168858183. The reversal of 28168858181 is 18185886182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21541432900 + 6627425281 = 146770^2 + 81409^2 .

It is a cyclic number.

It is not a de Polignac number, because 28168858181 - 2¹⁴ = 28168841797 is a prime.

It is a super-2 number, since 2×28168858181² (a number of 22 digits) contains 22 as substring.

Together with 28168858183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28168858183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14084429090 + 14084429091.

It is an arithmetic number, because the mean of its divisors is an integer number (14084429091).

Almost surely, 2^28168858181 is an apocalyptic number.

It is an amenable number.

28168858181 is a deficient number, since it is larger than the sum of its proper divisors (1).

28168858181 is an equidigital number, since it uses as much as digits as its factorization.

28168858181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1966080, while the sum is 56.

The spelling of 28168858181 in words is "twenty-eight billion, one hundred sixty-eight million, eight hundred fifty-eight thousand, one hundred eighty-one".