166690025 has 24 divisors (see below), whose sum is σ = 211277400. Its totient is φ = 130429440.

The previous prime is 166690019. The next prime is 166690031. The reversal of 166690025 is 520096661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (166690019) and next prime (166690031).

It can be written as a sum of positive squares in 12 ways, for example, as 130051216 + 36638809 = 11404^2 + 6053^2 .

It is not a de Polignac number, because 166690025 - 2⁴ = 166690009 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 271619 + ... + 272231.

It is an arithmetic number, because the mean of its divisors is an integer number (8803225).

Almost surely, 2^166690025 is an apocalyptic number.

It is an amenable number.

166690025 is a deficient number, since it is larger than the sum of its proper divisors (44587375).

166690025 is a wasteful number, since it uses less digits than its factorization.

166690025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 840 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 166690025 is about 12910.8491200231. The cubic root of 166690025 is about 550.3469161206.

The spelling of 166690025 in words is "one hundred sixty-six million, six hundred ninety thousand, twenty-five".