1216404 has 48 divisors (see below), whose sum is σ = 3606400. Its totient is φ = 347328.

The previous prime is 1216393. The next prime is 1216417. The reversal of 1216404 is 4046121.

1216404 is a `hidden beast` number, since 1 + 21 + 640 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49 + ... + 1560.

2^1216404 is an apocalyptic number.

1216404 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1216404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1803200).

1216404 is an abundant number, since it is smaller than the sum of its proper divisors (2389996).

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

1216404 is a wasteful number, since it uses less digits than its factorization.

1216404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1629 (or 1621 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1216404 is about 1102.9070677079. The cubic root of 1216404 is about 106.7478851912.

The spelling of 1216404 in words is "one million, two hundred sixteen thousand, four hundred four".