166725648709 has 2 divisors, whose sum is σ = 166725648710. Its totient is φ = 166725648708.

The previous prime is 166725648707. The next prime is 166725648769. The reversal of 166725648709 is 907846527661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101074398084 + 65651250625 = 317922^2 + 256225^2 .

It is a cyclic number.

It is not a de Polignac number, because 166725648709 - 2¹ = 166725648707 is a prime.

Together with 166725648707, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166725648707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83362824354 + 83362824355.

It is an arithmetic number, because the mean of its divisors is an integer number (83362824355).

Almost surely, 2^166725648709 is an apocalyptic number.

It is an amenable number.

166725648709 is a deficient number, since it is larger than the sum of its proper divisors (1).

166725648709 is an equidigital number, since it uses as much as digits as its factorization.

166725648709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30481920, while the sum is 61.

The spelling of 166725648709 in words is "one hundred sixty-six billion, seven hundred twenty-five million, six hundred forty-eight thousand, seven hundred nine".