28881161 has 2 divisors, whose sum is σ = 28881162. Its totient is φ = 28881160.

The previous prime is 28881143. The next prime is 28881163. The reversal of 28881161 is 16118882.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22505536 + 6375625 = 4744^2 + 2525^2 .

It is a cyclic number.

It is not a de Polignac number, because 28881161 - 2¹⁴ = 28864777 is a prime.

It is a super-4 number, since 4×28881161⁴ (a number of 31 digits) contains 4444 as substring.

Together with 28881163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28881163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14440580 + 14440581.

It is an arithmetic number, because the mean of its divisors is an integer number (14440581).

Almost surely, 2^28881161 is an apocalyptic number.

It is an amenable number.

28881161 is a deficient number, since it is larger than the sum of its proper divisors (1).

28881161 is an equidigital number, since it uses as much as digits as its factorization.

28881161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6144, while the sum is 35.

The square root of 28881161 is about 5374.1195557970. The cubic root of 28881161 is about 306.8114401239.

The spelling of 28881161 in words is "twenty-eight million, eight hundred eighty-one thousand, one hundred sixty-one".