389999989 has 2 divisors, whose sum is σ = 389999990. Its totient is φ = 389999988.

The previous prime is 389999977. The next prime is 389999999. The reversal of 389999989 is 989999983.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249103089 + 140896900 = 15783^2 + 11870^2 .

It is a cyclic number.

It is not a de Polignac number, because 389999989 - 2⁷ = 389999861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (389999999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194999994 + 194999995.

It is an arithmetic number, because the mean of its divisors is an integer number (194999995).

Almost surely, 2^389999989 is an apocalyptic number.

It is an amenable number.

389999989 is a deficient number, since it is larger than the sum of its proper divisors (1).

389999989 is an equidigital number, since it uses as much as digits as its factorization.

389999989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 102036672, while the sum is 73.

The square root of 389999989 is about 19748.4173796282. The cubic root of 389999989 is about 730.6143505373.

The spelling of 389999989 in words is "three hundred eighty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-nine".