16991856 has 100 divisors (see below), whose sum is σ = 56234992. Its totient is φ = 4852224.

The previous prime is 16991851. The next prime is 16991861. The reversal of 16991856 is 65819961.

It is an interprime number because it is at equal distance from previous prime (16991851) and next prime (16991861).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16991851) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8136 + ... + 10008.

Almost surely, 2^16991856 is an apocalyptic number.

16991856 is a gapful number since it is divisible by the number (16) 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 16991856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28117496).

16991856 is an abundant number, since it is smaller than the sum of its proper divisors (39243136).

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

16991856 is a wasteful number, since it uses less digits than its factorization.

16991856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900 (or 1885 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 16991856 is about 4122.1179022439. The cubic root of 16991856 is about 257.0870926696.

The spelling of 16991856 in words is "sixteen million, nine hundred ninety-one thousand, eight hundred fifty-six".