90090000 has 600 divisors, whose sum is σ = 423014592. Its totient is φ = 17280000.

The previous prime is 90089971. The next prime is 90090043. The reversal of 90090000 is 9009.

It is a tau number, because it is divible by the number of its divisors (600).

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 6929994 + ... + 6930006.

Almost surely, 2^90090000 is an apocalyptic number.

90090000 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 90090000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211507296).

90090000 is an abundant number, since it is smaller than the sum of its proper divisors (332924592).

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

90090000 is a wasteful number, since it uses less digits than its factorization.

90090000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 18.

The square root of 90090000 is about 9491.5752117338. The cubic root of 90090000 is about 448.2898050482.

Adding to 90090000 its reverse (9009), we get a palindrome (90099009).

Multiplying 90090000 by its reverse (9009), we get a square (811620810000 = 900900²).

90090000 divided by its reverse (9009) gives a 4-th power (10000 = 10⁴).

It can be divided in two parts, 900 and 90000, that multiplied together give a square (81000000 = 9000²).

The spelling of 90090000 in words is "ninety million, ninety thousand".