172318819997 has 2 divisors, whose sum is σ = 172318819998. Its totient is φ = 172318819996.

The previous prime is 172318819991. The next prime is 172318820071. The reversal of 172318819997 is 799918813271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133999191481 + 38319628516 = 366059^2 + 195754^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172318819997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172318819991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86159409998 + 86159409999.

It is an arithmetic number, because the mean of its divisors is an integer number (86159409999).

Almost surely, 2^172318819997 is an apocalyptic number.

It is an amenable number.

172318819997 is a deficient number, since it is larger than the sum of its proper divisors (1).

172318819997 is an equidigital number, since it uses as much as digits as its factorization.

172318819997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13716864, while the sum is 65.

The spelling of 172318819997 in words is "one hundred seventy-two billion, three hundred eighteen million, eight hundred nineteen thousand, nine hundred ninety-seven".