166145736248509 has 2 divisors, whose sum is σ = 166145736248510. Its totient is φ = 166145736248508.

The previous prime is 166145736248449. The next prime is 166145736248533. The reversal of 166145736248509 is 905842637541661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 113699099828484 + 52446636420025 = 10662978^2 + 7242005^2 .

It is a cyclic number.

It is not a de Polignac number, because 166145736248509 - 2²¹ = 166145734151357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166145736248309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83072868124254 + 83072868124255.

It is an arithmetic number, because the mean of its divisors is an integer number (83072868124255).

It is a 1-persistent number, because it is pandigital, but 2⋅166145736248509 = 332291472497018 is not.

Almost surely, 2^{166145736248509} is an apocalyptic number.

It is an amenable number.

166145736248509 is a deficient number, since it is larger than the sum of its proper divisors (1).

166145736248509 is an equidigital number, since it uses as much as digits as its factorization.

166145736248509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 261273600, while the sum is 67.

The spelling of 166145736248509 in words is "one hundred sixty-six trillion, one hundred forty-five billion, seven hundred thirty-six million, two hundred forty-eight thousand, five hundred nine".