21182371436173 has 2 divisors, whose sum is σ = 21182371436174. Its totient is φ = 21182371436172.

The previous prime is 21182371436153. The next prime is 21182371436257. The reversal of 21182371436173 is 37163417328112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15390854841924 + 5791516594249 = 3923118^2 + 2406557^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21182371436173 is a prime.

It is a super-2 number, since 2×21182371436173² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21182371436143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10591185718086 + 10591185718087.

It is an arithmetic number, because the mean of its divisors is an integer number (10591185718087).

Almost surely, 2^{21182371436173} is an apocalyptic number.

It is an amenable number.

21182371436173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21182371436173 is an equidigital number, since it uses as much as digits as its factorization.

21182371436173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1016064, while the sum is 49.

The spelling of 21182371436173 in words is "twenty-one trillion, one hundred eighty-two billion, three hundred seventy-one million, four hundred thirty-six thousand, one hundred seventy-three".