16691979 has 16 divisors (see below), whose sum is σ = 23061024. Its totient is φ = 10732800.

The previous prime is 16691963. The next prime is 16692019. The reversal of 16691979 is 97919661.

It is not a de Polignac number, because 16691979 - 2⁴ = 16691963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16691959) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8839 + ... + 10559.

It is an arithmetic number, because the mean of its divisors is an integer number (1441314).

Almost surely, 2^16691979 is an apocalyptic number.

16691979 is a deficient number, since it is larger than the sum of its proper divisors (6369045).

16691979 is a wasteful number, since it uses less digits than its factorization.

16691979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1838.

The product of its digits is 183708, while the sum is 48.

The square root of 16691979 is about 4085.5818435077. The cubic root of 16691979 is about 255.5657259202.

The spelling of 16691979 in words is "sixteen million, six hundred ninety-one thousand, nine hundred seventy-nine".