1221142200 has 48 divisors (see below), whose sum is σ = 3785542680. Its totient is φ = 325637760.

The previous prime is 1221142177. The next prime is 1221142229. The reversal of 1221142200 is 22411221.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221142200.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1017019 + ... + 1018218.

Almost surely, 2^1221142200 is an apocalyptic number.

1221142200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221142200 is an abundant number, since it is smaller than the sum of its proper divisors (2564400480).

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

1221142200 is a wasteful number, since it uses less digits than its factorization.

1221142200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2035256 (or 2035247 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 1221142200 is about 34944.8451134069. The cubic root of 1221142200 is about 1068.8630891582.

Adding to 1221142200 its reverse (22411221), we get a palindrome (1243553421).

The spelling of 1221142200 in words is "one billion, two hundred twenty-one million, one hundred forty-two thousand, two hundred".