16678891 has 4 divisors (see below), whose sum is σ = 16700872. Its totient is φ = 16656912.

The previous prime is 16678889. The next prime is 16678901. The reversal of 16678891 is 19887661.

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

It is a cyclic number.

It is not a de Polignac number, because 16678891 - 2¹ = 16678889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16678801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9810 + ... + 11383.

It is an arithmetic number, because the mean of its divisors is an integer number (4175218).

Almost surely, 2^16678891 is an apocalyptic number.

16678891 is a deficient number, since it is larger than the sum of its proper divisors (21981).

16678891 is an equidigital number, since it uses as much as digits as its factorization.

16678891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21980.

The product of its digits is 145152, while the sum is 46.

The square root of 16678891 is about 4083.9797991665. The cubic root of 16678891 is about 255.4989130153.

The spelling of 16678891 in words is "sixteen million, six hundred seventy-eight thousand, eight hundred ninety-one".