789999989 has 2 divisors, whose sum is σ = 789999990. Its totient is φ = 789999988.

The previous prime is 789999983. The next prime is 790000019. The reversal of 789999989 is 989999987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 747202225 + 42797764 = 27335^2 + 6542^2 .

It is a cyclic number.

It is not a de Polignac number, because 789999989 - 2⁸ = 789999733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (789999983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 394999994 + 394999995.

It is an arithmetic number, because the mean of its divisors is an integer number (394999995).

Almost surely, 2^789999989 is an apocalyptic number.

It is an amenable number.

789999989 is a deficient number, since it is larger than the sum of its proper divisors (1).

789999989 is an equidigital number, since it uses as much as digits as its factorization.

789999989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 238085568, while the sum is 77.

The square root of 789999989 is about 28106.9384494292. The cubic root of 789999989 is about 924.4335422470.

It can be divided in two parts, 78999 and 9989, that added together give a palindrome (88988).

The spelling of 789999989 in words is "seven hundred eighty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-nine".