166825661 has 4 divisors (see below), whose sum is σ = 172578300. Its totient is φ = 161073024.

The previous prime is 166825657. The next prime is 166825691. The reversal of 166825661 is 166528661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 127825636 + 39000025 = 11306^2 + 6245^2 .

It is a cyclic number.

It is not a de Polignac number, because 166825661 - 2² = 166825657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166825621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2876276 + ... + 2876333.

It is an arithmetic number, because the mean of its divisors is an integer number (43144575).

Almost surely, 2^166825661 is an apocalyptic number.

It is an amenable number.

166825661 is a deficient number, since it is larger than the sum of its proper divisors (5752639).

166825661 is an equidigital number, since it uses as much as digits as its factorization.

166825661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5752638.

The product of its digits is 103680, while the sum is 41.

The square root of 166825661 is about 12916.1008435208. The cubic root of 166825661 is about 550.4961484391.

The spelling of 166825661 in words is "one hundred sixty-six million, eight hundred twenty-five thousand, six hundred sixty-one".