990558720 has 400 divisors, whose sum is σ = 3769935048. Its totient is φ = 247726080.

The previous prime is 990558719. The next prime is 990558721. The reversal of 990558720 is 27855099.

It is a happy number.

990558720 is a `hidden beast` number, since 9 + 90 + 558 + 7 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (990558719) and next prime (990558721).

It can be written as a sum of positive squares in 4 ways, for example, as 940771584 + 49787136 = 30672^2 + 7056^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (990558721) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3524980 + ... + 3525260.

Almost surely, 2^990558720 is an apocalyptic number.

990558720 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 990558720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1884967524).

990558720 is an abundant number, since it is smaller than the sum of its proper divisors (2779376328).

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

990558720 is a wasteful number, since it uses less digits than its factorization.

990558720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The square root of 990558720 is about 31473.1428363931. The cubic root of 990558720 is about 996.8429501919.

The spelling of 990558720 in words is "nine hundred ninety million, five hundred fifty-eight thousand, seven hundred twenty".