16681793 has 4 divisors (see below), whose sum is σ = 17088708. Its totient is φ = 16274880.

The previous prime is 16681789. The next prime is 16681799. The reversal of 16681793 is 39718661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4765489 + 11916304 = 2183^2 + 3452^2 .

It is a cyclic number.

It is not a de Polignac number, because 16681793 - 2² = 16681789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 406873 = 16681793 / (1 + 6 + 6 + 8 + 1 + 7 + 9 + 3).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16681793.

It is not an unprimeable number, because it can be changed into a prime (16681799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203396 + ... + 203477.

It is an arithmetic number, because the mean of its divisors is an integer number (4272177).

Almost surely, 2^16681793 is an apocalyptic number.

It is an amenable number.

16681793 is a deficient number, since it is larger than the sum of its proper divisors (406915).

16681793 is an equidigital number, since it uses as much as digits as its factorization.

16681793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406914.

The product of its digits is 54432, while the sum is 41.

The square root of 16681793 is about 4084.3350744032. The cubic root of 16681793 is about 255.5137304442.

The spelling of 16681793 in words is "sixteen million, six hundred eighty-one thousand, seven hundred ninety-three".