1220656 has 40 divisors (see below), whose sum is σ = 2571264. Its totient is φ = 559680.

The previous prime is 1220623. The next prime is 1220657. The reversal of 1220656 is 6560221.

It is not an unprimeable number, because it can be changed into a prime (1220657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11355 + ... + 11461.

2^1220656 is an apocalyptic number.

1220656 is a gapful number since it is divisible by the number (16) 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 1220656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1285632).

1220656 is an abundant number, since it is smaller than the sum of its proper divisors (1350608).

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

1220656 is a wasteful number, since it uses less digits than its factorization.

1220656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 1220656 is about 1104.8330190576. The cubic root of 1220656 is about 106.8721213729.

Adding to 1220656 its reverse (6560221), we get a palindrome (7780877).

The spelling of 1220656 in words is "one million, two hundred twenty thousand, six hundred fifty-six".