166251340361 has 2 divisors, whose sum is σ = 166251340362. Its totient is φ = 166251340360.

The previous prime is 166251340357. The next prime is 166251340369. The reversal of 166251340361 is 163043152661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122486700361 + 43764640000 = 349981^2 + 209200^2 .

It is an emirp because it is prime and its reverse (163043152661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166251340361 - 2² = 166251340357 is a prime.

It is a super-2 number, since 2×166251340361² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166251340369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83125670180 + 83125670181.

It is an arithmetic number, because the mean of its divisors is an integer number (83125670181).

Almost surely, 2^166251340361 is an apocalyptic number.

It is an amenable number.

166251340361 is a deficient number, since it is larger than the sum of its proper divisors (1).

166251340361 is an equidigital number, since it uses as much as digits as its factorization.

166251340361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 38.

The spelling of 166251340361 in words is "one hundred sixty-six billion, two hundred fifty-one million, three hundred forty thousand, three hundred sixty-one".