1220663808 has 480 divisors, whose sum is σ = 4504211712. Its totient is φ = 309657600.

The previous prime is 1220663789. The next prime is 1220663813. The reversal of 1220663808 is 8083660221.

1220663808 is a `hidden beast` number, since 12 + 2 + 0 + 6 + 638 + 0 + 8 = 666.

It is a super-2 number, since 2×1220663808² = 2980040264322121728, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17192413 + ... + 17192483.

Almost surely, 2^1220663808 is an apocalyptic number.

1220663808 is a gapful number since it is divisible by the number (18) 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 1220663808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2252105856).

1220663808 is an abundant number, since it is smaller than the sum of its proper divisors (3283547904).

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

1220663808 is a wasteful number, since it uses less digits than its factorization.

1220663808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1220663808 is about 34937.9994848016. Note that the first 3 decimals coincide. The cubic root of 1220663808 is about 1068.7234924379.

Adding to 1220663808 its sum of digits (36), we get a square (1220663844 = 34938²).

The spelling of 1220663808 in words is "one billion, two hundred twenty million, six hundred sixty-three thousand, eight hundred eight".