221212123200 has 672 divisors, whose sum is σ = 845765867520. Its totient is φ = 56136960000.

The previous prime is 221212123159. The next prime is 221212123201. The reversal of 221212123200 is 2321212122.

221212123200 is a `hidden beast` number, since 221 + 2 + 121 + 2 + 320 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (221212123201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 249393157 + ... + 249394043.

It is an arithmetic number, because the mean of its divisors is an integer number (1258580160).

Almost surely, 2^221212123200 is an apocalyptic number.

221212123200 is a gapful number since it is divisible by the number (20) 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 221212123200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (422882933760).

221212123200 is an abundant number, since it is smaller than the sum of its proper divisors (624553744320).

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

221212123200 is a wasteful number, since it uses less digits than its factorization.

221212123200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1192 (or 1171 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 221212123200 its reverse (2321212122), we get a palindrome (223533335322).

The spelling of 221212123200 in words is "two hundred twenty-one billion, two hundred twelve million, one hundred twenty-three thousand, two hundred".