28185994489 has 2 divisors, whose sum is σ = 28185994490. Its totient is φ = 28185994488.

The previous prime is 28185994477. The next prime is 28185994493. The reversal of 28185994489 is 98449958182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20301975225 + 7884019264 = 142485^2 + 88792^2 .

It is a cyclic number.

It is not a de Polignac number, because 28185994489 - 2⁵ = 28185994457 is a prime.

It is a super-2 number, since 2×28185994489² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28185994789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14092997244 + 14092997245.

It is an arithmetic number, because the mean of its divisors is an integer number (14092997245).

Almost surely, 2^28185994489 is an apocalyptic number.

It is an amenable number.

28185994489 is a deficient number, since it is larger than the sum of its proper divisors (1).

28185994489 is an equidigital number, since it uses as much as digits as its factorization.

28185994489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 59719680, while the sum is 67.

The spelling of 28185994489 in words is "twenty-eight billion, one hundred eighty-five million, nine hundred ninety-four thousand, four hundred eighty-nine".