166556487 has 4 divisors (see below), whose sum is σ = 222075320. Its totient is φ = 111037656.

The previous prime is 166556431. The next prime is 166556513. The reversal of 166556487 is 784655661.

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

It is not a de Polignac number, because 166556487 - 2¹⁴ = 166540103 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 (166556407) 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, 27759412 + ... + 27759417.

It is an arithmetic number, because the mean of its divisors is an integer number (55518830).

Almost surely, 2^166556487 is an apocalyptic number.

166556487 is a deficient number, since it is larger than the sum of its proper divisors (55518833).

166556487 is an equidigital number, since it uses as much as digits as its factorization.

166556487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55518832.

The product of its digits is 1209600, while the sum is 48.

The square root of 166556487 is about 12905.6765417393. The cubic root of 166556487 is about 550.1999130021.

The spelling of 166556487 in words is "one hundred sixty-six million, five hundred fifty-six thousand, four hundred eighty-seven".