28428689 has 2 divisors, whose sum is σ = 28428690. Its totient is φ = 28428688.

The previous prime is 28428683. The next prime is 28428739. The reversal of 28428689 is 98682482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25331089 + 3097600 = 5033^2 + 1760^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28428689 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28428683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14214344 + 14214345.

It is an arithmetic number, because the mean of its divisors is an integer number (14214345).

Almost surely, 2^28428689 is an apocalyptic number.

It is an amenable number.

28428689 is a deficient number, since it is larger than the sum of its proper divisors (1).

28428689 is an equidigital number, since it uses as much as digits as its factorization.

28428689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 442368, while the sum is 47.

The square root of 28428689 is about 5331.8560558215. The cubic root of 28428689 is about 305.2007600580.

The spelling of 28428689 in words is "twenty-eight million, four hundred twenty-eight thousand, six hundred eighty-nine".