166251601 has 4 divisors (see below), whose sum is σ = 166776372. Its totient is φ = 165726832.

The previous prime is 166251599. The next prime is 166251623. The reversal of 166251601 is 106152661.

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 58507201 + 107744400 = 7649^2 + 10380^2 .

It is a cyclic number.

It is not a de Polignac number, because 166251601 - 2¹ = 166251599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166251601.

It is not an unprimeable number, because it can be changed into a prime (166251641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 261910 + ... + 262543.

It is an arithmetic number, because the mean of its divisors is an integer number (41694093).

Almost surely, 2^166251601 is an apocalyptic number.

It is an amenable number.

166251601 is a deficient number, since it is larger than the sum of its proper divisors (524771).

166251601 is an equidigital number, since it uses as much as digits as its factorization.

166251601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524770.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 166251601 is about 12893.8590421952. The cubic root of 166251601 is about 549.8639895090.

The spelling of 166251601 in words is "one hundred sixty-six million, two hundred fifty-one thousand, six hundred one".