1220644 has 12 divisors (see below), whose sum is σ = 2144268. Its totient is φ = 608000.

The previous prime is 1220623. The next prime is 1220657. The reversal of 1220644 is 4460221.

It can be written as a sum of positive squares in 2 ways, for example, as 580644 + 640000 = 762^2 + 800^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1224 + ... + 1984.

It is an arithmetic number, because the mean of its divisors is an integer number (178689).

2^1220644 is an apocalyptic number.

It is an amenable number.

1220644 is a deficient number, since it is larger than the sum of its proper divisors (923624).

1220644 is a wasteful number, since it uses less digits than its factorization.

1220644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166 (or 1164 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 1220644 is about 1104.8275883594. The cubic root of 1220644 is about 106.8717711597.

Adding to 1220644 its reverse (4460221), we get a palindrome (5680865).

The spelling of 1220644 in words is "one million, two hundred twenty thousand, six hundred forty-four".