1221122200 has 24 divisors (see below), whose sum is σ = 2839109580. Its totient is φ = 488448800.

The previous prime is 1221122179. The next prime is 1221122207. The reversal of 1221122200 is 22211221.

It is a happy number.

It is a super-2 number, since 2×1221122200² = 2982278854665680000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221122207) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3052606 + ... + 3053005.

Almost surely, 2^1221122200 is an apocalyptic number.

1221122200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221122200 is an abundant number, since it is smaller than the sum of its proper divisors (1617987380).

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

1221122200 is a wasteful number, since it uses less digits than its factorization.

1221122200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6105627 (or 6105618 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1221122200 is about 34944.5589469949. The cubic root of 1221122200 is about 1068.8572538077.

Adding to 1221122200 its reverse (22211221), we get a palindrome (1243333421).

The spelling of 1221122200 in words is "one billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred".