166073987 has 4 divisors (see below), whose sum is σ = 166110816. Its totient is φ = 166037160.

The previous prime is 166073977. The next prime is 166073989. The reversal of 166073987 is 789370661.

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

It is not a de Polignac number, because 166073987 - 2¹⁸ = 165811843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166073989) 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, 10523 + ... + 21044.

It is an arithmetic number, because the mean of its divisors is an integer number (41527704).

Almost surely, 2^166073987 is an apocalyptic number.

166073987 is a deficient number, since it is larger than the sum of its proper divisors (36829).

166073987 is an equidigital number, since it uses as much as digits as its factorization.

166073987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36828.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 166073987 is about 12886.9696593109. The cubic root of 166073987 is about 549.6681049939.

The spelling of 166073987 in words is "one hundred sixty-six million, seventy-three thousand, nine hundred eighty-seven".