90240 has 64 divisors (see below), whose sum is σ = 293760. Its totient is φ = 23552.

The previous prime is 90239. The next prime is 90247. The reversal of 90240 is 4209.

90240 = T₉₁ + T₉₂ + ... + T₁₀₈.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (90247) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1897 + ... + 1943.

It is an arithmetic number, because the mean of its divisors is an integer number (4590).

2⁹⁰²⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146880).

90240 is an abundant number, since it is smaller than the sum of its proper divisors (203520).

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

90240 is a wasteful number, since it uses less digits than its factorization.

90240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 90240 is about 300.3997336883. The cubic root of 90240 is about 44.8538468182.

Adding to 90240 its reverse (4209), we get a palindrome (94449).

The spelling of 90240 in words is "ninety thousand, two hundred forty".