21221201010000 has 200 divisors, whose sum is σ = 68543077993984. Its totient is φ = 5655830400000.

The previous prime is 21221201009993. The next prime is 21221201010013. The reversal of 21221201010000 is 1010212212.

It is a tau number, because it is divible by the number of its divisors (200).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 53833617 + ... + 54226383.

Almost surely, 2^{21221201010000} is an apocalyptic number.

21221201010000 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 21221201010000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34271538996992).

21221201010000 is an abundant number, since it is smaller than the sum of its proper divisors (47321876983984).

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

21221201010000 is a wasteful number, since it uses less digits than its factorization.

21221201010000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394599 (or 394578 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21221201010000 its reverse (1010212212), we get a palindrome (21222211222212).

It can be divided in two parts, 212 and 21201010000, that added together give a palindrome (21201010212).

The spelling of 21221201010000 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred one million, ten thousand".