72640 has 28 divisors (see below), whose sum is σ = 173736. Its totient is φ = 28928.

The previous prime is 72623. The next prime is 72643. The reversal of 72640 is 4627.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207 + ... + 433.

2⁷²⁶⁴⁰ 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 72640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86868).

72640 is an abundant number, since it is smaller than the sum of its proper divisors (101096).

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

72640 is a wasteful number, since it uses less digits than its factorization.

72640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 72640 is about 269.5180884468. The cubic root of 72640 is about 41.7245772532.

The spelling of 72640 in words is "seventy-two thousand, six hundred forty".