72705 has 16 divisors (see below), whose sum is σ = 120384. Its totient is φ = 37440.

The previous prime is 72701. The next prime is 72707. The reversal of 72705 is 50727.

It is not a de Polignac number, because 72705 - 2² = 72701 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (72701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 490 + ... + 620.

It is an arithmetic number, because the mean of its divisors is an integer number (7524).

It is a Proth number, since it is equal to 71 ⋅ 2¹⁰ + 1 and 71 < 2¹⁰.

2⁷²⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

72705 is a deficient number, since it is larger than the sum of its proper divisors (47679).

72705 is a wasteful number, since it uses less digits than its factorization.

72705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176.

The product of its (nonzero) digits is 490, while the sum is 21.

The square root of 72705 is about 269.6386470816. The cubic root of 72705 is about 41.7370189244.

It can be divided in two parts, 72 and 705, that added together give a palindrome (777).

The spelling of 72705 in words is "seventy-two thousand, seven hundred five".