72109 has 2 divisors, whose sum is σ = 72110. Its totient is φ = 72108.

The previous prime is 72103. The next prime is 72139. The reversal of 72109 is 90127.

72109 is nontrivially palindromic in base 11.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64009 + 8100 = 253^2 + 90^2 .

It is an emirp because it is prime and its reverse (90127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72109 - 2³ = 72101 is a prime.

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

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36054 + 36055.

It is an arithmetic number, because the mean of its divisors is an integer number (36055).

2⁷²¹⁰⁹ is an apocalyptic number.

It is an amenable number.

72109 is a deficient number, since it is larger than the sum of its proper divisors (1).

72109 is an equidigital number, since it uses as much as digits as its factorization.

72109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 19.

The square root of 72109 is about 268.5311899948. The cubic root of 72109 is about 41.6226593146.

It can be divided in two parts, 72 and 109, that added together give a palindrome (181).

The spelling of 72109 in words is "seventy-two thousand, one hundred nine".