221220121000 has 64 divisors (see below), whose sum is σ = 517768926480. Its totient is φ = 88468588800.

The previous prime is 221220120983. The next prime is 221220121009. The reversal of 221220121000 is 121022122.

It is a happy number.

221220121000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 3879545796 + 217340575204 = 62286^2 + 466198^2 .

It is not an unprimeable number, because it can be changed into a prime (221220121009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5055214 + ... + 5098786.

Almost surely, 2^221220121000 is an apocalyptic number.

221220121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221220121000 is an abundant number, since it is smaller than the sum of its proper divisors (296548805480).

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

221220121000 is a wasteful number, since it uses less digits than its factorization.

221220121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48671 (or 48657 counting only the distinct ones).

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

Adding to 221220121000 its reverse (121022122), we get a palindrome (221341143122).

The spelling of 221220121000 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred twenty-one thousand".