16665880 has 96 divisors (see below), whose sum is σ = 47647440. Its totient is φ = 5187840.

The previous prime is 16665863. The next prime is 16665881. The reversal of 16665880 is 8856661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16665881) 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 23 ways as a sum of consecutive naturals, for example, 21174 + ... + 21946.

Almost surely, 2^16665880 is an apocalyptic number.

16665880 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 16665880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23823720).

16665880 is an abundant number, since it is smaller than the sum of its proper divisors (30981560).

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

16665880 is a wasteful number, since it uses less digits than its factorization.

16665880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809 (or 798 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 16665880 is about 4082.3865569052. The cubic root of 16665880 is about 255.4324585340.

The spelling of 16665880 in words is "sixteen million, six hundred sixty-five thousand, eight hundred eighty".