73440 has 96 divisors (see below), whose sum is σ = 272160. Its totient is φ = 18432.

The previous prime is 73433. The next prime is 73453. The reversal of 73440 is 4437.

It is a Cunningham number, because it is equal to 271²-1.

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

73440 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4312 + ... + 4328.

It is an arithmetic number, because the mean of its divisors is an integer number (2835).

2⁷³⁴⁴⁰ 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 73440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136080).

73440 is an abundant number, since it is smaller than the sum of its proper divisors (198720).

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

73440 is a wasteful number, since it uses less digits than its factorization.

73440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41 (or 27 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 73440 is about 270.9981549753. The cubic root of 73440 is about 41.8771922815.

Adding to 73440 its reverse (4437), we get a palindrome (77877).

The spelling of 73440 in words is "seventy-three thousand, four hundred forty", and thus it is an iban number.