28131778163 has 2 divisors, whose sum is σ = 28131778164. Its totient is φ = 28131778162.

The previous prime is 28131778159. The next prime is 28131778187. The reversal of 28131778163 is 36187713182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28131778163 - 2² = 28131778159 is a prime.

It is a super-2 number, since 2×28131778163² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28131778123) 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 as a sum of consecutive naturals, namely, 14065889081 + 14065889082.

It is an arithmetic number, because the mean of its divisors is an integer number (14065889082).

Almost surely, 2^28131778163 is an apocalyptic number.

28131778163 is a deficient number, since it is larger than the sum of its proper divisors (1).

28131778163 is an equidigital number, since it uses as much as digits as its factorization.

28131778163 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 47.

The spelling of 28131778163 in words is "twenty-eight billion, one hundred thirty-one million, seven hundred seventy-eight thousand, one hundred sixty-three".