28173949 has 2 divisors, whose sum is σ = 28173950. Its totient is φ = 28173948.

The previous prime is 28173931. The next prime is 28173991. The reversal of 28173949 is 94937182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26163225 + 2010724 = 5115^2 + 1418^2 .

It is a cyclic number.

It is not a de Polignac number, because 28173949 - 2²³ = 19785341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28173449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14086974 + 14086975.

It is an arithmetic number, because the mean of its divisors is an integer number (14086975).

Almost surely, 2^28173949 is an apocalyptic number.

It is an amenable number.

28173949 is a deficient number, since it is larger than the sum of its proper divisors (1).

28173949 is an equidigital number, since it uses as much as digits as its factorization.

28173949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 28173949 is about 5307.9138086446. The cubic root of 28173949 is about 304.2864228337.

The spelling of 28173949 in words is "twenty-eight million, one hundred seventy-three thousand, nine hundred forty-nine".