16641891 has 24 divisors (see below), whose sum is σ = 28920320. Its totient is φ = 9008496.

The previous prime is 16641881. The next prime is 16641893. The reversal of 16641891 is 19814661.

It is a happy number.

16641891 is a `hidden beast` number, since 1 + 6 + 641 + 8 + 9 + 1 = 666.

It is not a de Polignac number, because 16641891 - 2⁷ = 16641763 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16641893) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5755 + ... + 8148.

Almost surely, 2^16641891 is an apocalyptic number.

16641891 is a deficient number, since it is larger than the sum of its proper divisors (12278429).

16641891 is a wasteful number, since it uses less digits than its factorization.

16641891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13935 (or 13932 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 16641891 is about 4079.4473890467. The cubic root of 16641891 is about 255.3098425141.

The spelling of 16641891 in words is "sixteen million, six hundred forty-one thousand, eight hundred ninety-one".