21201200120100 has 576 divisors, whose sum is σ = 86696311080960. Its totient is φ = 3852533145600.

The previous prime is 21201200120063. The next prime is 21201200120117. The reversal of 21201200120100 is 102100210212.

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

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3847804 + ... + 7563596.

It is an arithmetic number, because the mean of its divisors is an integer number (150514428960).

Almost surely, 2^{21201200120100} is an apocalyptic number.

21201200120100 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 21201200120100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43348155540480).

21201200120100 is an abundant number, since it is smaller than the sum of its proper divisors (65495110960860).

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

21201200120100 is a wasteful number, since it uses less digits than its factorization.

21201200120100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3715860 (or 3715853 counting only the distinct ones).

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

Adding to 21201200120100 its reverse (102100210212), we get a palindrome (21303300330312).

The spelling of 21201200120100 in words is "twenty-one trillion, two hundred one billion, two hundred million, one hundred twenty thousand, one hundred".