21121211220000 has 960 divisors, whose sum is σ = 71499910204800. Its totient is φ = 5456056320000.

The previous prime is 21121211219959. The next prime is 21121211220007. The reversal of 21121211220000 is 2211212112.

It is a super-2 number, since 2×21121211220000² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21121211220007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 76249859862 + ... + 76249860138.

It is an arithmetic number, because the mean of its divisors is an integer number (74479073130).

Almost surely, 2^{21121211220000} is an apocalyptic number.

21121211220000 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 21121211220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35749955102400).

21121211220000 is an abundant number, since it is smaller than the sum of its proper divisors (50378698984800).

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

21121211220000 is a wasteful number, since it uses less digits than its factorization.

21121211220000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639 (or 616 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21121211220000 its reverse (2211212112), we get a palindrome (21123422432112).

It can be divided in two parts, 211212112 and 20000, that added together give a palindrome (211232112).

The spelling of 21121211220000 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred eleven million, two hundred twenty thousand".