16404 has 12 divisors (see below), whose sum is σ = 38304. Its totient is φ = 5464.

The previous prime is 16381. The next prime is 16411. The reversal of 16404 is 40461.

16404 = T₆₀ + T₆₁ + ... + T₆₇.

It is a tau number, because it is divible by the number of its divisors (12).

It is a plaindrome in base 9.

It is a nialpdrome in base 7.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 672 + ... + 695.

It is an arithmetic number, because the mean of its divisors is an integer number (3192).

2¹⁶⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

16404 is an abundant number, since it is smaller than the sum of its proper divisors (21900).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19152).

16404 is a wasteful number, since it uses less digits than its factorization.

16404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1374 (or 1372 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 16404 is about 128.0781011727. The cubic root of 16404 is about 25.4087472714.

Adding to 16404 its reverse (40461), we get a palindrome (56865).

The spelling of 16404 in words is "sixteen thousand, four hundred four".