221221012000 has 48 divisors (see below), whose sum is σ = 543540036312. Its totient is φ = 88488403200.

The previous prime is 221221011989. The next prime is 221221012007. The reversal of 221221012000 is 210122122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 89762556816 + 131458455184 = 299604^2 + 362572^2 .

It is not an unprimeable number, because it can be changed into a prime (221221012007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27648627 + ... + 27656626.

Almost surely, 2^221221012000 is an apocalyptic number.

221221012000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221221012000 is an abundant number, since it is smaller than the sum of its proper divisors (322319024312).

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

221221012000 is an equidigital number, since it uses as much as digits as its factorization.

221221012000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55305278 (or 55305260 counting only the distinct ones).

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

Adding to 221221012000 its reverse (210122122), we get a palindrome (221431134122).

The spelling of 221221012000 in words is "two hundred twenty-one billion, two hundred twenty-one million, twelve thousand".