16991520 has 192 divisors, whose sum is σ = 66044160. Its totient is φ = 3575808.

The previous prime is 16991509. The next prime is 16991531. The reversal of 16991520 is 2519961.

It is an interprime number because it is at equal distance from previous prime (16991509) and next prime (16991531).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43486 + ... + 43874.

It is an arithmetic number, because the mean of its divisors is an integer number (343980).

Almost surely, 2^16991520 is an apocalyptic number.

16991520 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 16991520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33022080).

16991520 is an abundant number, since it is smaller than the sum of its proper divisors (49052640).

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

16991520 is a wasteful number, since it uses less digits than its factorization.

16991520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 16991520 is about 4122.0771462941. The cubic root of 16991520 is about 257.0853980964.

The spelling of 16991520 in words is "sixteen million, nine hundred ninety-one thousand, five hundred twenty".