21122012221000 has 128 divisors (see below), whose sum is σ = 51172493580000. Its totient is φ = 8150661120000.

The previous prime is 21122012220977. The next prime is 21122012221019. The reversal of 21122012221000 is 12221022112.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 10958655468996 + 10163356752004 = 3310386^2 + 3188002^2 .

It is a super-2 number, since 2×21122012221000² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 34525776 + ... + 35132224.

Almost surely, 2^{21122012221000} is an apocalyptic number.

21122012221000 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 21122012221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25586246790000).

21122012221000 is an abundant number, since it is smaller than the sum of its proper divisors (30050481359000).

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

21122012221000 is a wasteful number, since it uses less digits than its factorization.

21122012221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607700 (or 607686 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21122012221000 its reverse (12221022112), we get a palindrome (21134233243112).

The spelling of 21122012221000 in words is "twenty-one trillion, one hundred twenty-two billion, twelve million, two hundred twenty-one thousand".