16651818 has 48 divisors (see below), whose sum is σ = 38263680. Its totient is φ = 5432508.

The previous prime is 16651807. The next prime is 16651849. The reversal of 16651818 is 81815661.

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 23 ways as a sum of consecutive naturals, for example, 354271 + ... + 354317.

It is an arithmetic number, because the mean of its divisors is an integer number (797160).

Almost surely, 2^16651818 is an apocalyptic number.

16651818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 16651818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19131840).

16651818 is an abundant number, since it is smaller than the sum of its proper divisors (21611862).

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

16651818 is an frugal number, since it uses more digits than its factorization.

16651818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82 (or 52 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 16651818 is about 4080.6639165704. The cubic root of 16651818 is about 255.3605971034.

It can be divided in two parts, 166 and 51818, that added together give a square (51984 = 228²).

The spelling of 16651818 in words is "sixteen million, six hundred fifty-one thousand, eight hundred eighteen".