72840 has 32 divisors (see below), whose sum is σ = 218880. Its totient is φ = 19392.

The previous prime is 72823. The next prime is 72859. The reversal of 72840 is 4827.

It is a happy number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 72840.

It is an unprimeable number.

72840 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 7 ways as a sum of consecutive naturals, for example, 184 + ... + 423.

It is an arithmetic number, because the mean of its divisors is an integer number (6840).

2⁷²⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

72840 is an abundant number, since it is smaller than the sum of its proper divisors (146040).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109440).

72840 is a wasteful number, since it uses less digits than its factorization.

72840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621 (or 617 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 72840 is about 269.8888660171. Note that the first 4 decimals coincide. The cubic root of 72840 is about 41.7628356437.

The spelling of 72840 in words is "seventy-two thousand, eight hundred forty".