166166425 has 6 divisors (see below), whose sum is σ = 206046398. Its totient is φ = 132933120.

The previous prime is 166166389. The next prime is 166166431. The reversal of 166166425 is 524661661.

It can be written as a sum of positive squares in 3 ways, for example, as 683929 + 165482496 = 827^2 + 12864^2 .

It is not a de Polignac number, because 166166425 - 2⁹ = 166165913 is a prime.

It is a super-2 number, since 2×166166425² = 55222561594561250, which contains 22 as substring.

It is a Duffinian 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 5 ways as a sum of consecutive naturals, for example, 3323304 + ... + 3323353.

Almost surely, 2^166166425 is an apocalyptic number.

It is an amenable number.

166166425 is a deficient number, since it is larger than the sum of its proper divisors (39879973).

166166425 is an equidigital number, since it uses as much as digits as its factorization.

166166425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6646667 (or 6646662 counting only the distinct ones).

The product of its digits is 51840, while the sum is 37.

The square root of 166166425 is about 12890.5556513286. Note that the first 3 decimals coincide. The cubic root of 166166425 is about 549.7700691787.

It can be divided in two parts, 1661 and 66425, that added together give a palindrome (68086).

The spelling of 166166425 in words is "one hundred sixty-six million, one hundred sixty-six thousand, four hundred twenty-five".