16631220 has 48 divisors (see below), whose sum is σ = 47013120. Its totient is φ = 4392576.

The previous prime is 16631203. The next prime is 16631233. The reversal of 16631220 is 2213661.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5269 + ... + 7811.

It is an arithmetic number, because the mean of its divisors is an integer number (979440).

Almost surely, 2^16631220 is an apocalyptic number.

16631220 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 16631220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23506560).

16631220 is an abundant number, since it is smaller than the sum of its proper divisors (30381900).

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

16631220 is a wasteful number, since it uses less digits than its factorization.

16631220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2664 (or 2662 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 16631220 is about 4078.1392815842. The cubic root of 16631220 is about 255.2552615003.

Adding to 16631220 its reverse (2213661), we get a palindrome (18844881).

The spelling of 16631220 in words is "sixteen million, six hundred thirty-one thousand, two hundred twenty".