28531716181 has 2 divisors, whose sum is σ = 28531716182. Its totient is φ = 28531716180.

The previous prime is 28531716079. The next prime is 28531716193. The reversal of 28531716181 is 18161713582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27969552081 + 562164100 = 167241^2 + 23710^2 .

It is a cyclic number.

It is not a de Polignac number, because 28531716181 - 2⁷ = 28531716053 is a prime.

It is a super-2 number, since 2×28531716181² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28531716581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14265858090 + 14265858091.

It is an arithmetic number, because the mean of its divisors is an integer number (14265858091).

Almost surely, 2^28531716181 is an apocalyptic number.

It is an amenable number.

28531716181 is a deficient number, since it is larger than the sum of its proper divisors (1).

28531716181 is an equidigital number, since it uses as much as digits as its factorization.

28531716181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 43.

The spelling of 28531716181 in words is "twenty-eight billion, five hundred thirty-one million, seven hundred sixteen thousand, one hundred eighty-one".