1221220200 has 96 divisors (see below), whose sum is σ = 3907964160. Its totient is φ = 315148800.

The previous prime is 1221220199. The next prime is 1221220229. The reversal of 1221220200 is 20221221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14229 + ... + 51428.

It is an arithmetic number, because the mean of its divisors is an integer number (40707960).

Almost surely, 2^1221220200 is an apocalyptic number.

1221220200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221220200 is an abundant number, since it is smaller than the sum of its proper divisors (2686743960).

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

1221220200 is a wasteful number, since it uses less digits than its factorization.

1221220200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65707 (or 65698 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 1221220200 is about 34945.9611400230. The cubic root of 1221220200 is about 1068.8858464167.

Adding to 1221220200 its reverse (20221221), we get a palindrome (1241441421).

The spelling of 1221220200 in words is "one billion, two hundred twenty-one million, two hundred twenty thousand, two hundred".