16556720 has 40 divisors (see below), whose sum is σ = 39397776. Its totient is φ = 6467328.

The previous prime is 16556719. The next prime is 16556753. The reversal of 16556720 is 2765561.

It is a happy number.

16556720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1034 + ... + 5846.

Almost surely, 2^16556720 is an apocalyptic number.

16556720 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 16556720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19698888).

16556720 is an abundant number, since it is smaller than the sum of its proper divisors (22841056).

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

16556720 is a wasteful number, since it uses less digits than its factorization.

16556720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4869 (or 4863 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 16556720 is about 4068.9949619040. The cubic root of 16556720 is about 254.8735500191.

The spelling of 16556720 in words is "sixteen million, five hundred fifty-six thousand, seven hundred twenty".