16809881 has 4 divisors (see below), whose sum is σ = 18338064. Its totient is φ = 15281700.

The previous prime is 16809869. The next prime is 16809887. The reversal of 16809881 is 18890861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16809881 - 2⁶ = 16809817 is a prime.

It is a super-2 number, since 2×16809881² = 565144198468322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16809887) 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, 764075 + ... + 764096.

It is an arithmetic number, because the mean of its divisors is an integer number (4584516).

Almost surely, 2^16809881 is an apocalyptic number.

16809881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16809881 is a deficient number, since it is larger than the sum of its proper divisors (1528183).

16809881 is a wasteful number, since it uses less digits than its factorization.

16809881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1528182.

The product of its (nonzero) digits is 27648, while the sum is 41.

The square root of 16809881 is about 4099.9854877792. The cubic root of 16809881 is about 256.1660350722.

The spelling of 16809881 in words is "sixteen million, eight hundred nine thousand, eight hundred eighty-one".