1220904 has 48 divisors (see below), whose sum is σ = 3419520. Its totient is φ = 393120.

The previous prime is 1220903. The next prime is 1220917. The reversal of 1220904 is 4090221.

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

It is not an unprimeable number, because it can be changed into a prime (1220903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1959 + ... + 2505.

It is an arithmetic number, because the mean of its divisors is an integer number (71240).

2^1220904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1709760).

1220904 is an abundant number, since it is smaller than the sum of its proper divisors (2198616).

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

1220904 is a wasteful number, since it uses less digits than its factorization.

1220904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590 (or 583 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 1220904 is about 1104.9452475123. The cubic root of 1220904 is about 106.8793585993.

The spelling of 1220904 in words is "one million, two hundred twenty thousand, nine hundred four".