90018720 has 144 divisors (see below), whose sum is σ = 335174112. Its totient is φ = 21818880.

The previous prime is 90018703. The next prime is 90018767. The reversal of 90018720 is 2781009.

It is a tau number, because it is divible by the number of its divisors (144).

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 23 ways as a sum of consecutive naturals, for example, 12999 + ... + 18681.

It is an arithmetic number, because the mean of its divisors is an integer number (2327598).

Almost surely, 2^90018720 is an apocalyptic number.

90018720 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 90018720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167587056).

90018720 is an abundant number, since it is smaller than the sum of its proper divisors (245155392).

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

90018720 is a wasteful number, since it uses less digits than its factorization.

90018720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5715 (or 5704 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 90018720 is about 9487.8195598357. The cubic root of 90018720 is about 448.1715435746.

Adding to 90018720 its reverse (2781009), we get a palindrome (92799729).

The spelling of 90018720 in words is "ninety million, eighteen thousand, seven hundred twenty".