90001800009 has 27 divisors (see below), whose sum is σ = 142911139917. Its totient is φ = 54540545400.

The previous prime is 90001799977. The next prime is 90001800029. The reversal of 90001800009 is 90000810009.

The square root of 90001800009 is 300003.

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

It is not a de Polignac number, because 90001800009 - 2⁵ = 90001799977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90001800029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9895554 + ... + 9904644.

Almost surely, 2^90001800009 is an apocalyptic number.

90001800009 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

90001800009 is the 300003-rd square number.

90001800009 is the 150002-nd centered octagonal number.

It is an amenable number.

90001800009 is a deficient number, since it is larger than the sum of its proper divisors (52909339908).

90001800009 is an frugal number, since it uses more digits than its factorization.

90001800009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18210 (or 9105 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The spelling of 90001800009 in words is "ninety billion, one million, eight hundred thousand, nine".