663611220 has 36 divisors (see below), whose sum is σ = 2012954580. Its totient is φ = 176962944.

The previous prime is 663611191. The next prime is 663611231. The reversal of 663611220 is 22116366.

663611220 is a `hidden beast` number, since 6 + 636 + 1 + 1 + 2 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 446815044 + 216796176 = 21138^2 + 14724^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1843185 + ... + 1843544.

It is an arithmetic number, because the mean of its divisors is an integer number (55915405).

Almost surely, 2^663611220 is an apocalyptic number.

663611220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

663611220 is an abundant number, since it is smaller than the sum of its proper divisors (1349343360).

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

663611220 is a wasteful number, since it uses less digits than its factorization.

663611220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3686744 (or 3686739 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 663611220 is about 25760.6525538465. The cubic root of 663611220 is about 872.2438313863.

Adding to 663611220 its reverse (22116366), we get a palindrome (685727586).

The spelling of 663611220 in words is "six hundred sixty-three million, six hundred eleven thousand, two hundred twenty".