16991816 has 16 divisors (see below), whose sum is σ = 32538240. Its totient is φ = 8314960.

The previous prime is 16991809. The next prime is 16991851. The reversal of 16991816 is 61819961.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22220 + ... + 22971.

It is an arithmetic number, because the mean of its divisors is an integer number (2033640).

Almost surely, 2^16991816 is an apocalyptic number.

It is an amenable number.

16991816 is a deficient number, since it is larger than the sum of its proper divisors (15546424).

16991816 is a wasteful number, since it uses less digits than its factorization.

16991816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45244 (or 45240 counting only the distinct ones).

The product of its digits is 23328, while the sum is 41.

The square root of 16991816 is about 4122.1130503663. The cubic root of 16991816 is about 257.0868909359.

The spelling of 16991816 in words is "sixteen million, nine hundred ninety-one thousand, eight hundred sixteen".