1221606 has 12 divisors (see below), whose sum is σ = 2646852. Its totient is φ = 407196.

The previous prime is 1221601. The next prime is 1221631. The reversal of 1221606 is 6061221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 67867 = 1221606 / (1 + 2 + 2 + 1 + 6 + 0 + 6).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33916 + ... + 33951.

It is an arithmetic number, because the mean of its divisors is an integer number (220571).

2^1221606 is an apocalyptic number.

1221606 is an abundant number, since it is smaller than the sum of its proper divisors (1425246).

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

1221606 is a wasteful number, since it uses less digits than its factorization.

1221606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67875 (or 67872 counting only the distinct ones).

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

The square root of 1221606 is about 1105.2628646616. The cubic root of 1221606 is about 106.8998393071.

Adding to 1221606 its reverse (6061221), we get a palindrome (7282827).

It can be divided in two parts, 122 and 1606, that added together give a cube (1728 = 12³).

The spelling of 1221606 in words is "one million, two hundred twenty-one thousand, six hundred six".