166721063 has 4 divisors (see below), whose sum is σ = 167825328. Its totient is φ = 165616800.

The previous prime is 166721011. The next prime is 166721077. The reversal of 166721063 is 360127661.

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

It is not a de Polignac number, because 166721063 - 2⁶ = 166720999 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 (166711063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 551906 + ... + 552207.

It is an arithmetic number, because the mean of its divisors is an integer number (41956332).

Almost surely, 2^166721063 is an apocalyptic number.

166721063 is a deficient number, since it is larger than the sum of its proper divisors (1104265).

166721063 is a wasteful number, since it uses less digits than its factorization.

166721063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1104264.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 166721063 is about 12912.0510764169. The cubic root of 166721063 is about 550.3810725485.

The spelling of 166721063 in words is "one hundred sixty-six million, seven hundred twenty-one thousand, sixty-three".