72540 has 72 divisors (see below), whose sum is σ = 244608. Its totient is φ = 17280.

The previous prime is 72533. The next prime is 72547. The reversal of 72540 is 4527.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (72533) and next prime (72547).

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 an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72547) by changing a digit.

72540 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 23 ways as a sum of consecutive naturals, for example, 2325 + ... + 2355.

2⁷²⁵⁴⁰ 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 72540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122304).

72540 is an abundant number, since it is smaller than the sum of its proper divisors (172068).

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

72540 is a wasteful number, since it uses less digits than its factorization.

72540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 72540 is about 269.3325082496. The cubic root of 72540 is about 41.7054217197.

The spelling of 72540 in words is "seventy-two thousand, five hundred forty".