28072189 has 2 divisors, whose sum is σ = 28072190. Its totient is φ = 28072188.

The previous prime is 28072169. The next prime is 28072201. The reversal of 28072189 is 98127082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23522500 + 4549689 = 4850^2 + 2133^2 .

It is a cyclic number.

It is not a de Polignac number, because 28072189 - 2⁵ = 28072157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28072169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14036094 + 14036095.

It is an arithmetic number, because the mean of its divisors is an integer number (14036095).

Almost surely, 2^28072189 is an apocalyptic number.

It is an amenable number.

28072189 is a deficient number, since it is larger than the sum of its proper divisors (1).

28072189 is an equidigital number, since it uses as much as digits as its factorization.

28072189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 28072189 is about 5298.3194505428. The cubic root of 28072189 is about 303.9196355264.

The spelling of 28072189 in words is "twenty-eight million, seventy-two thousand, one hundred eighty-nine".