72170173 has 2 divisors, whose sum is σ = 72170174. Its totient is φ = 72170172.

The previous prime is 72170149. The next prime is 72170177. The reversal of 72170173 is 37107127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67272804 + 4897369 = 8202^2 + 2213^2 .

It is an emirp because it is prime and its reverse (37107127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72170173 - 2⁵ = 72170141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72170177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36085086 + 36085087.

It is an arithmetic number, because the mean of its divisors is an integer number (36085087).

Almost surely, 2^72170173 is an apocalyptic number.

It is an amenable number.

72170173 is a deficient number, since it is larger than the sum of its proper divisors (1).

72170173 is an equidigital number, since it uses as much as digits as its factorization.

72170173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2058, while the sum is 28.

The square root of 72170173 is about 8495.3029963622. The cubic root of 72170173 is about 416.3442605324.

The spelling of 72170173 in words is "seventy-two million, one hundred seventy thousand, one hundred seventy-three".