28539989 has 2 divisors, whose sum is σ = 28539990. Its totient is φ = 28539988.

The previous prime is 28539967. The next prime is 28540021. The reversal of 28539989 is 98993582.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28536964 + 3025 = 5342^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 28539989 - 2⁸ = 28539733 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28539989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28539949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14269994 + 14269995.

It is an arithmetic number, because the mean of its divisors is an integer number (14269995).

Almost surely, 2^28539989 is an apocalyptic number.

It is an amenable number.

28539989 is a deficient number, since it is larger than the sum of its proper divisors (1).

28539989 is an equidigital number, since it uses as much as digits as its factorization.

28539989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 53.

The square root of 28539989 is about 5342.2831261550. The cubic root of 28539989 is about 305.5985344184.

The spelling of 28539989 in words is "twenty-eight million, five hundred thirty-nine thousand, nine hundred eighty-nine".