21002101200 has 180 divisors, whose sum is σ = 75582849888. Its totient is φ = 5600534400.

The previous prime is 21002101181. The next prime is 21002101249. The reversal of 21002101200 is 210120012.

It is a tau number, because it is divible by the number of its divisors (180).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 10836 + ... + 205235.

Almost surely, 2^21002101200 is an apocalyptic number.

21002101200 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 21002101200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37791424944).

21002101200 is an abundant number, since it is smaller than the sum of its proper divisors (54580748688).

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

21002101200 is a wasteful number, since it uses less digits than its factorization.

21002101200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216104 (or 216081 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21002101200 its reverse (210120012), we get a palindrome (21212221212).

The spelling of 21002101200 in words is "twenty-one billion, two million, one hundred one thousand, two hundred".