90000000000 has 363 divisors, whose sum is σ = 324841301941. Its totient is φ = 24000000000.

The previous prime is 89999999993. The next prime is 90000000019. The reversal of 90000000000 is 9.

The square root of 90000000000 is 300000.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 5 ways, for example, as 517653504 + 89482346496 = 22752^2 + 299136^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 90000000000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 32 ways as a sum of consecutive naturals, for example, 17999999998 + ... + 18000000002.

Almost surely, 2^90000000000 is an apocalyptic number.

90000000000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

90000000000 is the 300000-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90000000000

90000000000 is an abundant number, since it is smaller than the sum of its proper divisors (234841301941).

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

90000000000 is an frugal number, since it uses more digits than its factorization.

90000000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 9.

The spelling of 90000000000 in words is "ninety billion", and thus it is an aban number and an uban number.