16656891 has 8 divisors (see below), whose sum is σ = 22253904. Its totient is φ = 11082240.

The previous prime is 16656881. The next prime is 16656907. The reversal of 16656891 is 19865661.

It is a happy number.

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

It is not a de Polignac number, because 16656891 - 2²³ = 8268283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16656881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3766 + ... + 6891.

It is an arithmetic number, because the mean of its divisors is an integer number (2781738).

Almost surely, 2^16656891 is an apocalyptic number.

16656891 is a deficient number, since it is larger than the sum of its proper divisors (5597013).

16656891 is a wasteful number, since it uses less digits than its factorization.

16656891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11181.

The product of its digits is 77760, while the sum is 42.

The square root of 16656891 is about 4081.2854592640. The cubic root of 16656891 is about 255.3865264600.

The spelling of 16656891 in words is "sixteen million, six hundred fifty-six thousand, eight hundred ninety-one".