166725109 has 2 divisors, whose sum is σ = 166725110. Its totient is φ = 166725108.

The previous prime is 166725107. The next prime is 166725113. The reversal of 166725109 is 901527661.

166725109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158004900 + 8720209 = 12570^2 + 2953^2 .

It is a cyclic number.

It is not a de Polignac number, because 166725109 - 2¹ = 166725107 is a prime.

Together with 166725107, 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 (166725101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83362554 + 83362555.

It is an arithmetic number, because the mean of its divisors is an integer number (83362555).

Almost surely, 2^166725109 is an apocalyptic number.

It is an amenable number.

166725109 is a deficient number, since it is larger than the sum of its proper divisors (1).

166725109 is an equidigital number, since it uses as much as digits as its factorization.

166725109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 166725109 is about 12912.2077508070. The cubic root of 166725109 is about 550.3855247430.

The spelling of 166725109 in words is "one hundred sixty-six million, seven hundred twenty-five thousand, one hundred nine".