16687720 has 64 divisors (see below), whose sum is σ = 43390080. Its totient is φ = 5657856.

The previous prime is 16687717. The next prime is 16687721. The reversal of 16687720 is 2778661.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 16687720.

It is not an unprimeable number, because it can be changed into a prime (16687721) 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 15 ways as a sum of consecutive naturals, for example, 29682 + ... + 30238.

It is an arithmetic number, because the mean of its divisors is an integer number (677970).

Almost surely, 2^16687720 is an apocalyptic number.

16687720 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 16687720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21695040).

16687720 is an abundant number, since it is smaller than the sum of its proper divisors (26702360).

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

16687720 is a wasteful number, since it uses less digits than its factorization.

16687720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 16687720 is about 4085.0605870660. The cubic root of 16687720 is about 255.5439879942.

The spelling of 16687720 in words is "sixteen million, six hundred eighty-seven thousand, seven hundred twenty".