16921008 has 160 divisors (see below), whose sum is σ = 54996480. Its totient is φ = 4942080.

The previous prime is 16920983. The next prime is 16921013. The reversal of 16921008 is 80012961.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129103 + ... + 129233.

It is an arithmetic number, because the mean of its divisors is an integer number (343728).

Almost surely, 2^16921008 is an apocalyptic number.

16921008 is a gapful number since it is divisible by the number (18) 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 16921008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27498240).

16921008 is an abundant number, since it is smaller than the sum of its proper divisors (38075472).

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

16921008 is a wasteful number, since it uses less digits than its factorization.

16921008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 16921008 is about 4113.5152850087. The cubic root of 16921008 is about 256.7292843980.

Adding to 16921008 its reverse (80012961), we get a palindrome (96933969).

The spelling of 16921008 in words is "sixteen million, nine hundred twenty-one thousand, eight".