21000120121002 has 64 divisors (see below), whose sum is σ = 47409459926400. Its totient is φ = 6142800814080.

The previous prime is 21000120120887. The next prime is 21000120121039. The reversal of 21000120121002 is 20012102100012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6930078 + ... + 9488214.

It is an arithmetic number, because the mean of its divisors is an integer number (740772811350).

Almost surely, 2^{21000120121002} is an apocalyptic number.

21000120121002 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000120121002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23704729963200).

21000120121002 is an abundant number, since it is smaller than the sum of its proper divisors (26409339805398).

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

21000120121002 is a wasteful number, since it uses less digits than its factorization.

21000120121002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2562471.

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

Adding to 21000120121002 its reverse (20012102100012), we get a palindrome (41012222221014).

The spelling of 21000120121002 in words is "twenty-one trillion, one hundred twenty million, one hundred twenty-one thousand, two".