72165105 has 12 divisors (see below), whose sum is σ = 125086260. Its totient is φ = 38488032.

The previous prime is 72165101. The next prime is 72165127. The reversal of 72165105 is 50156127.

72165105 is a `hidden beast` number, since 7 + 2 + 1 + 651 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 52664049 + 19501056 = 7257^2 + 4416^2 .

It is not a de Polignac number, because 72165105 - 2² = 72165101 is a prime.

It is a super-2 number, since 2×72165105² = 10415604759322050, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72165101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 801790 + ... + 801879.

It is an arithmetic number, because the mean of its divisors is an integer number (10423855).

Almost surely, 2^72165105 is an apocalyptic number.

It is an amenable number.

72165105 is a deficient number, since it is larger than the sum of its proper divisors (52921155).

72165105 is a wasteful number, since it uses less digits than its factorization.

72165105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603680 (or 1603677 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 72165105 is about 8495.0047086508. The cubic root of 72165105 is about 416.3345146683.

It can be divided in two parts, 7216 and 5105, that added together give a palindrome (12321).

The spelling of 72165105 in words is "seventy-two million, one hundred sixty-five thousand, one hundred five".