72155217162173 has 2 divisors, whose sum is σ = 72155217162174. Its totient is φ = 72155217162172.

The previous prime is 72155217162109. The next prime is 72155217162187. The reversal of 72155217162173 is 37126171255127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58352075155609 + 13803142006564 = 7638853^2 + 3715258^2 .

It is an emirp because it is prime and its reverse (37126171255127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72155217162173 - 2⁶ = 72155217162109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72155217162103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36077608581086 + 36077608581087.

It is an arithmetic number, because the mean of its divisors is an integer number (36077608581087).

Almost surely, 2^{72155217162173} is an apocalyptic number.

It is an amenable number.

72155217162173 is a deficient number, since it is larger than the sum of its proper divisors (1).

72155217162173 is an equidigital number, since it uses as much as digits as its factorization.

72155217162173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1234800, while the sum is 50.

The spelling of 72155217162173 in words is "seventy-two trillion, one hundred fifty-five billion, two hundred seventeen million, one hundred sixty-two thousand, one hundred seventy-three".