21010001221200 has 240 divisors, whose sum is σ = 68077940161536. Its totient is φ = 5538302246400.

The previous prime is 21010001221163. The next prime is 21010001221229. The reversal of 21010001221200 is 212210001012.

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 59272495 + ... + 59625905.

Almost surely, 2^{21010001221200} is an apocalyptic number.

21010001221200 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 21010001221200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34038970080768).

21010001221200 is an abundant number, since it is smaller than the sum of its proper divisors (47067938940336).

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

21010001221200 is a wasteful number, since it uses less digits than its factorization.

21010001221200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354002 (or 353991 counting only the distinct ones).

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

Adding to 21010001221200 its reverse (212210001012), we get a palindrome (21222211222212).

The spelling of 21010001221200 in words is "twenty-one trillion, ten billion, one million, two hundred twenty-one thousand, two hundred".