16991940 has 96 divisors (see below), whose sum is σ = 56770560. Its totient is φ = 3712896.

The previous prime is 16991927. The next prime is 16991951. The reversal of 16991940 is 4919961.

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, 8781 + ... + 10539.

It is an arithmetic number, because the mean of its divisors is an integer number (591360).

Almost surely, 2^16991940 is an apocalyptic number.

16991940 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 16991940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28385280).

16991940 is an abundant number, since it is smaller than the sum of its proper divisors (39778620).

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

16991940 is a wasteful number, since it uses less digits than its factorization.

16991940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801 (or 1799 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 39.

The square root of 16991940 is about 4122.1280911684. The cubic root of 16991940 is about 257.0875163094.

The spelling of 16991940 in words is "sixteen million, nine hundred ninety-one thousand, nine hundred forty".