166003657 has 4 divisors (see below), whose sum is σ = 175768596. Its totient is φ = 156238720.

The previous prime is 166003633. The next prime is 166003661. The reversal of 166003657 is 756300661.

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 79495056 + 86508601 = 8916^2 + 9301^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166003657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166003687) 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, 4882444 + ... + 4882477.

It is an arithmetic number, because the mean of its divisors is an integer number (43942149).

Almost surely, 2^166003657 is an apocalyptic number.

166003657 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

166003657 is a deficient number, since it is larger than the sum of its proper divisors (9764939).

166003657 is an equidigital number, since it uses as much as digits as its factorization.

166003657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9764938.

The product of its (nonzero) digits is 22680, while the sum is 34.

The square root of 166003657 is about 12884.2406450671. The cubic root of 166003657 is about 549.5905017986.

The spelling of 166003657 in words is "one hundred sixty-six million, three thousand, six hundred fifty-seven".