72165005 has 24 divisors (see below), whose sum is σ = 96210072. Its totient is φ = 51920000.

The previous prime is 72165001. The next prime is 72165029. The reversal of 72165005 is 50056127.

It can be written as a sum of positive squares in 4 ways, for example, as 41550916 + 30614089 = 6446^2 + 5533^2 .

It is not a de Polignac number, because 72165005 - 2² = 72165001 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72165001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60515 + ... + 61695.

It is an arithmetic number, because the mean of its divisors is an integer number (4008753).

Almost surely, 2^72165005 is an apocalyptic number.

It is an amenable number.

72165005 is a deficient number, since it is larger than the sum of its proper divisors (24045067).

72165005 is a wasteful number, since it uses less digits than its factorization.

72165005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309 (or 1298 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 26.

The square root of 72165005 is about 8494.9988228369. The cubic root of 72165005 is about 416.3343223617.

It can be divided in two parts, 7216 and 5005, that added together give a palindrome (12221).

The spelling of 72165005 in words is "seventy-two million, one hundred sixty-five thousand, five".