166109725 has 6 divisors (see below), whose sum is σ = 205976090. Its totient is φ = 132887760.

The previous prime is 166109707. The next prime is 166109753. The reversal of 166109725 is 527901661.

166109725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 910116 + 165199609 = 954^2 + 12853^2 .

It is not a de Polignac number, because 166109725 - 2⁷ = 166109597 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3322170 + ... + 3322219.

Almost surely, 2^166109725 is an apocalyptic number.

It is an amenable number.

166109725 is a deficient number, since it is larger than the sum of its proper divisors (39866365).

166109725 is an equidigital number, since it uses as much as digits as its factorization.

166109725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6644399 (or 6644394 counting only the distinct ones).

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

The square root of 166109725 is about 12888.3561791254. The cubic root of 166109725 is about 549.7075304536.

It can be divided in two parts, 16610 and 9725, that added together give a triangular number (26335 = T₂₂₉).

The spelling of 166109725 in words is "one hundred sixty-six million, one hundred nine thousand, seven hundred twenty-five".