21010002000 has 320 divisors, whose sum is σ = 75308513280. Its totient is φ = 5004288000.

The previous prime is 21010001989. The next prime is 21010002017. The reversal of 21010002000 is 20001012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21010002000.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2413656 + ... + 2422344.

It is an arithmetic number, because the mean of its divisors is an integer number (235339104).

Almost surely, 2^21010002000 is an apocalyptic number.

21010002000 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 21010002000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37654256640).

21010002000 is an abundant number, since it is smaller than the sum of its proper divisors (54298511280).

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

21010002000 is a wasteful number, since it uses less digits than its factorization.

21010002000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8759 (or 8743 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 6.

Adding to 21010002000 its reverse (20001012), we get a palindrome (21030003012).

The spelling of 21010002000 in words is "twenty-one billion, ten million, two thousand".