16686720 has 96 divisors (see below), whose sum is σ = 57641220. Its totient is φ = 4448256.

The previous prime is 16686697. The next prime is 16686743. The reversal of 16686720 is 2768661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (16686697) and next prime (16686743).

It can be written as a sum of positive squares in 2 ways, for example, as 15303744 + 1382976 = 3912^2 + 1176^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 4312 + ... + 7208.

Almost surely, 2^16686720 is an apocalyptic number.

16686720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16686720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28820610).

16686720 is an abundant number, since it is smaller than the sum of its proper divisors (40954500).

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

16686720 is a wasteful number, since it uses less digits than its factorization.

16686720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2922 (or 2907 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 16686720 is about 4084.9381880268. The cubic root of 16686720 is about 255.5388834604.

The spelling of 16686720 in words is "sixteen million, six hundred eighty-six thousand, seven hundred twenty".