90288720 has 120 divisors (see below), whose sum is σ = 306844200. Its totient is φ = 23789568.

The previous prime is 90288713. The next prime is 90288721. The reversal of 90288720 is 2788209.

It can be written as a sum of positive squares in 4 ways, for example, as 2903616 + 87385104 = 1704^2 + 9348^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90288721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63376 + ... + 64784.

It is an arithmetic number, because the mean of its divisors is an integer number (2557035).

Almost surely, 2^90288720 is an apocalyptic number.

90288720 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 90288720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153422100).

90288720 is an abundant number, since it is smaller than the sum of its proper divisors (216555480).

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

90288720 is a wasteful number, since it uses less digits than its factorization.

90288720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517 (or 1508 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 90288720 is about 9502.0376762040. The cubic root of 90288720 is about 448.6191746777.

The spelling of 90288720 in words is "ninety million, two hundred eighty-eight thousand, seven hundred twenty".