21201121211000 has 128 divisors (see below), whose sum is σ = 50378123352960. Its totient is φ = 8349578496000.

The previous prime is 21201121210993. The next prime is 21201121211033. The reversal of 21201121211000 is 11212110212.

It is a congruent number.

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, 51839312 + ... + 52246688.

It is an arithmetic number, because the mean of its divisors is an integer number (393579088695).

Almost surely, 2^{21201121211000} is an apocalyptic number.

21201121211000 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 21201121211000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25189061676480).

21201121211000 is an abundant number, since it is smaller than the sum of its proper divisors (29177002141960).

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

21201121211000 is a wasteful number, since it uses less digits than its factorization.

21201121211000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408202 (or 408188 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21201121211000 its reverse (11212110212), we get a palindrome (21212333321212).

The spelling of 21201121211000 in words is "twenty-one trillion, two hundred one billion, one hundred twenty-one million, two hundred eleven thousand".