28430989 has 2 divisors, whose sum is σ = 28430990. Its totient is φ = 28430988.

The previous prime is 28430977. The next prime is 28431019. The reversal of 28430989 is 98903482.

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., 21696964 + 6734025 = 4658^2 + 2595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28430989 is a prime.

It is a super-2 number, since 2×28430989² = 1616642271036242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28430929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14215494 + 14215495.

It is an arithmetic number, because the mean of its divisors is an integer number (14215495).

Almost surely, 2^28430989 is an apocalyptic number.

It is an amenable number.

28430989 is a deficient number, since it is larger than the sum of its proper divisors (1).

28430989 is an equidigital number, since it uses as much as digits as its factorization.

28430989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 28430989 is about 5332.0717362016. The cubic root of 28430989 is about 305.2089905093.

The spelling of 28430989 in words is "twenty-eight million, four hundred thirty thousand, nine hundred eighty-nine".