1220655 has 16 divisors (see below), whose sum is σ = 2056320. Its totient is φ = 616608.

The previous prime is 1220623. The next prime is 1220657. The reversal of 1220655 is 5560221.

It is not a de Polignac number, because 1220655 - 2⁵ = 1220623 is a prime.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 1857 + ... + 2426.

It is an arithmetic number, because the mean of its divisors is an integer number (128520).

2^1220655 is an apocalyptic number.

1220655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1220655 is a deficient number, since it is larger than the sum of its proper divisors (835665).

1220655 is a wasteful number, since it uses less digits than its factorization.

1220655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4310.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 1220655 is about 1104.8325665005. The cubic root of 1220655 is about 106.8720921886.

Adding to 1220655 its reverse (5560221), we get a palindrome (6780876).

The spelling of 1220655 in words is "one million, two hundred twenty thousand, six hundred fifty-five".