168173053611721 has 2 divisors, whose sum is σ = 168173053611722. Its totient is φ = 168173053611720.

The previous prime is 168173053611707. The next prime is 168173053611727. The reversal of 168173053611721 is 127116350371861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86265829443600 + 81907224168121 = 9287940^2 + 9050261^2 .

It is a cyclic number.

It is not a de Polignac number, because 168173053611721 - 2¹⁹ = 168173053087433 is a prime.

It is a super-2 number, since 2×168173053611721² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (168173053611727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84086526805860 + 84086526805861.

It is an arithmetic number, because the mean of its divisors is an integer number (84086526805861).

Almost surely, 2^{168173053611721} is an apocalyptic number.

It is an amenable number.

168173053611721 is a deficient number, since it is larger than the sum of its proper divisors (1).

168173053611721 is an equidigital number, since it uses as much as digits as its factorization.

168173053611721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1270080, while the sum is 52.

The spelling of 168173053611721 in words is "one hundred sixty-eight trillion, one hundred seventy-three billion, fifty-three million, six hundred eleven thousand, seven hundred twenty-one".