999729990 has 192 divisors, whose sum is σ = 3073075200. Its totient is φ = 220776192.

The previous prime is 999729989. The next prime is 999730093. The reversal of 999729990 is 99927999.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

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 in 95 ways as a sum of consecutive naturals, for example, 2637621 + ... + 2637999.

It is an arithmetic number, because the mean of its divisors is an integer number (16005600).

Almost surely, 2^999729990 is an apocalyptic number.

999729990 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 999729990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1536537600).

999729990 is an abundant number, since it is smaller than the sum of its proper divisors (2073345210).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999729990 is a wasteful number, since it uses less digits than its factorization.

999729990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531 (or 528 counting only the distinct ones).

The product of its (nonzero) digits is 7440174, while the sum is 63.

The square root of 999729990 is about 31618.5070805059. The cubic root of 999729990 is about 999.9099885649.

The spelling of 999729990 in words is "nine hundred ninety-nine million, seven hundred twenty-nine thousand, nine hundred ninety".