16409181 has 4 divisors (see below), whose sum is σ = 21878912. Its totient is φ = 10939452.

The previous prime is 16409153. The next prime is 16409213. The reversal of 16409181 is 18190461.

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 not a de Polignac number, because 16409181 - 2¹⁸ = 16147037 is a prime.

It is a super-2 number, since 2×16409181² = 538522442181522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16409581) 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, 2734861 + ... + 2734866.

It is an arithmetic number, because the mean of its divisors is an integer number (5469728).

Almost surely, 2^16409181 is an apocalyptic number.

It is an amenable number.

16409181 is a deficient number, since it is larger than the sum of its proper divisors (5469731).

16409181 is an equidigital number, since it uses as much as digits as its factorization.

16409181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5469730.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 16409181 is about 4050.8247308419. The cubic root of 16409181 is about 254.1142200245.

The spelling of 16409181 in words is "sixteen million, four hundred nine thousand, one hundred eighty-one".