16991766 has 24 divisors (see below), whose sum is σ = 40162824. Its totient is φ = 5148960.

The previous prime is 16991759. The next prime is 16991773. The reversal of 16991766 is 66719961.

It is an interprime number because it is at equal distance from previous prime (16991759) and next prime (16991773).

It is a super-2 number, since 2×16991766² = 577440223597512, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42711 + ... + 43106.

It is an arithmetic number, because the mean of its divisors is an integer number (1673451).

Almost surely, 2^16991766 is an apocalyptic number.

16991766 is an abundant number, since it is smaller than the sum of its proper divisors (23171058).

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

16991766 is a wasteful number, since it uses less digits than its factorization.

16991766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85836 (or 85833 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 16991766 is about 4122.1069855112. The cubic root of 16991766 is about 257.0866387682.

The spelling of 16991766 in words is "sixteen million, nine hundred ninety-one thousand, seven hundred sixty-six".