1221685200 has 480 divisors, whose sum is σ = 4649702400. Its totient is φ = 304128000.

The previous prime is 1221685187. The next prime is 1221685219. The reversal of 1221685200 is 25861221.

It is a happy number.

1221685200 is a `hidden beast` number, since 122 + 16 + 8 + 520 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13726756 + ... + 13726844.

It is an arithmetic number, because the mean of its divisors is an integer number (9686880).

Almost surely, 2^1221685200 is an apocalyptic number.

1221685200 is a gapful number since it is divisible by the number (10) 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 1221685200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2324851200).

1221685200 is an abundant number, since it is smaller than the sum of its proper divisors (3428017200).

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

1221685200 is a wasteful number, since it uses less digits than its factorization.

1221685200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 1221685200 is about 34952.6136361789. The cubic root of 1221685200 is about 1069.0214945844.

The spelling of 1221685200 in words is "one billion, two hundred twenty-one million, six hundred eighty-five thousand, two hundred".