999929989 has 2 divisors, whose sum is σ = 999929990. Its totient is φ = 999929988.

The previous prime is 999929981. The next prime is 999930023. The reversal of 999929989 is 989929999.

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., 984390625 + 15539364 = 31375^2 + 3942^2 .

It is an emirp because it is prime and its reverse (989929999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999929989 - 2³ = 999929981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999929981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499964994 + 499964995.

It is an arithmetic number, because the mean of its divisors is an integer number (499964995).

Almost surely, 2^999929989 is an apocalyptic number.

It is an amenable number.

999929989 is a deficient number, since it is larger than the sum of its proper divisors (1).

999929989 is an equidigital number, since it uses as much as digits as its factorization.

999929989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 76527504, while the sum is 73.

The square root of 999929989 is about 31621.6696112017. The cubic root of 999929989 is about 999.9766624554.

The spelling of 999929989 in words is "nine hundred ninety-nine million, nine hundred twenty-nine thousand, nine hundred eighty-nine".