72805 has 4 divisors (see below), whose sum is σ = 87372. Its totient is φ = 58240.

The previous prime is 72797. The next prime is 72817. The reversal of 72805 is 50827.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47524 + 25281 = 218^2 + 159^2 .

It is not a de Polignac number, because 72805 - 2³ = 72797 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7276 + ... + 7285.

It is an arithmetic number, because the mean of its divisors is an integer number (21843).

2⁷²⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

72805 is a deficient number, since it is larger than the sum of its proper divisors (14567).

72805 is a wasteful number, since it uses less digits than its factorization.

72805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14566.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 72805 is about 269.8240167220. The cubic root of 72805 is about 41.7561454852.

Adding to 72805 its sum of digits (22), we get a palindrome (72827).

The spelling of 72805 in words is "seventy-two thousand, eight hundred five".