21002001200012 has 72 divisors (see below), whose sum is σ = 43156427806800. Its totient is φ = 8916475559040.

The previous prime is 21002001199973. The next prime is 21002001200017. The reversal of 21002001200012 is 21000210020012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21002001199966 and 21002001200002.

It is not an unprimeable number, because it can be changed into a prime (21002001200017) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9929087 + ... + 11857097.

It is an arithmetic number, because the mean of its divisors is an integer number (599394830650).

Almost surely, 2^{21002001200012} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002001200012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21578213903400).

21002001200012 is an abundant number, since it is smaller than the sum of its proper divisors (22154426606788).

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

21002001200012 is a wasteful number, since it uses less digits than its factorization.

21002001200012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1928551 (or 1928542 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21002001200012 its reverse (21000210020012), we get a palindrome (42002211220024).

The spelling of 21002001200012 in words is "twenty-one trillion, two billion, one million, two hundred thousand, twelve".