16721172 has 36 divisors (see below), whose sum is σ = 45520020. Its totient is φ = 5144832.

The previous prime is 16721167. The next prime is 16721189. The reversal of 16721172 is 27112761.

It can be written as a sum of positive squares in 2 ways, for example, as 992016 + 15729156 = 996^2 + 3966^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17397 + ... + 18332.

It is an arithmetic number, because the mean of its divisors is an integer number (1264445).

Almost surely, 2^16721172 is an apocalyptic number.

16721172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

16721172 is an abundant number, since it is smaller than the sum of its proper divisors (28798848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16721172 is a wasteful number, since it uses less digits than its factorization.

16721172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35752 (or 35747 counting only the distinct ones).

The product of its digits is 1176, while the sum is 27.

The square root of 16721172 is about 4089.1529685254. The cubic root of 16721172 is about 255.7146274783.

The spelling of 16721172 in words is "sixteen million, seven hundred twenty-one thousand, one hundred seventy-two".