28378171 has 2 divisors, whose sum is σ = 28378172. Its totient is φ = 28378170.

The previous prime is 28378139. The next prime is 28378183. The reversal of 28378171 is 17187382.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28378171 - 2⁵ = 28378139 is a prime.

It is equal to p_1763497 and since 28378171 and 1763497 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28378171.

It is not a weakly prime, because it can be changed into another prime (28378111) 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, 14189085 + 14189086.

It is an arithmetic number, because the mean of its divisors is an integer number (14189086).

Almost surely, 2^28378171 is an apocalyptic number.

28378171 is a deficient number, since it is larger than the sum of its proper divisors (1).

28378171 is an equidigital number, since it uses as much as digits as its factorization.

28378171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18816, while the sum is 37.

The square root of 28378171 is about 5327.1165746584. The cubic root of 28378171 is about 305.0198714993.

The spelling of 28378171 in words is "twenty-eight million, three hundred seventy-eight thousand, one hundred seventy-one".