21112121221000 has 32 divisors (see below), whose sum is σ = 49402363659480. Its totient is φ = 8444848488000.

The previous prime is 21112121220977. The next prime is 21112121221001. The reversal of 21112121221000 is 12212121112.

It can be written as a sum of positive squares in 4 ways, for example, as 5588789139844 + 15523332081156 = 2364062^2 + 3939966^2 .

It is not an unprimeable number, because it can be changed into a prime (21112121221001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10556059611 + ... + 10556061610.

Almost surely, 2^{21112121221000} is an apocalyptic number.

21112121221000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112121221000 is an abundant number, since it is smaller than the sum of its proper divisors (28290242438480).

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

21112121221000 is a wasteful number, since it uses less digits than its factorization.

21112121221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21112121242 (or 21112121228 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21112121221000 its reverse (12212121112), we get a palindrome (21124333342112).

The spelling of 21112121221000 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, two hundred twenty-one thousand".