1220646 has 16 divisors (see below), whose sum is σ = 2790144. Its totient is φ = 348744.

The previous prime is 1220623. The next prime is 1220657. The reversal of 1220646 is 6460221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 14490 + ... + 14573.

It is an arithmetic number, because the mean of its divisors is an integer number (174384).

2^1220646 is an apocalyptic number.

1220646 is an abundant number, since it is smaller than the sum of its proper divisors (1569498).

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

1220646 is a wasteful number, since it uses less digits than its factorization.

1220646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29075.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 1220646 is about 1104.8284934776. The cubic root of 1220646 is about 106.8718295287.

Adding to 1220646 its reverse (6460221), we get a palindrome (7680867).

The spelling of 1220646 in words is "one million, two hundred twenty thousand, six hundred forty-six".