28445689 has 2 divisors, whose sum is σ = 28445690. Its totient is φ = 28445688.

The previous prime is 28445639. The next prime is 28445701. The reversal of 28445689 is 98654482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 7469289 = 4580^2 + 2733^2 .

It is a cyclic number.

It is not a de Polignac number, because 28445689 - 2⁹ = 28445177 is a prime.

It is not a weakly prime, because it can be changed into another prime (28445639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14222844 + 14222845.

It is an arithmetic number, because the mean of its divisors is an integer number (14222845).

Almost surely, 2^28445689 is an apocalyptic number.

It is an amenable number.

28445689 is a deficient number, since it is larger than the sum of its proper divisors (1).

28445689 is an equidigital number, since it uses as much as digits as its factorization.

28445689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 552960, while the sum is 46.

The square root of 28445689 is about 5333.4500091404. The cubic root of 28445689 is about 305.2615833466.

It can be divided in two parts, 2844 and 5689, that multiplied together give a triangular number (16179516 = T₅₆₈₈).

The spelling of 28445689 in words is "twenty-eight million, four hundred forty-five thousand, six hundred eighty-nine".