16813409 has 4 divisors (see below), whose sum is σ = 16887060. Its totient is φ = 16739760.

The previous prime is 16813399. The next prime is 16813453. The reversal of 16813409 is 90431861.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7980625 + 8832784 = 2825^2 + 2972^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16813409 is a prime.

It is a super-3 number, since 3×16813409³ (a number of 23 digits) contains 333 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 (16813009) 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, 36482 + ... + 36939.

It is an arithmetic number, because the mean of its divisors is an integer number (4221765).

Almost surely, 2^16813409 is an apocalyptic number.

It is an amenable number.

16813409 is a deficient number, since it is larger than the sum of its proper divisors (73651).

16813409 is an equidigital number, since it uses as much as digits as its factorization.

16813409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73650.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 16813409 is about 4100.4157106323. The cubic root of 16813409 is about 256.1839549007.

The spelling of 16813409 in words is "sixteen million, eight hundred thirteen thousand, four hundred nine".