16993891 has 8 divisors (see below), whose sum is σ = 17245584. Its totient is φ = 16744320.

The previous prime is 16993877. The next prime is 16993903. The reversal of 16993891 is 19839961.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16993891 - 2¹³ = 16985699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16993831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21951 + ... + 22711.

It is an arithmetic number, because the mean of its divisors is an integer number (2155698).

Almost surely, 2^16993891 is an apocalyptic number.

16993891 is a deficient number, since it is larger than the sum of its proper divisors (251693).

16993891 is a wasteful number, since it uses less digits than its factorization.

16993891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061.

The product of its digits is 104976, while the sum is 46.

The square root of 16993891 is about 4122.3647339846. The cubic root of 16993891 is about 257.0973554557.

The spelling of 16993891 in words is "sixteen million, nine hundred ninety-three thousand, eight hundred ninety-one".