21001001002002 has 64 divisors (see below), whose sum is σ = 53396279439360. Its totient is φ = 5993490564432.

The previous prime is 21001001001979. The next prime is 21001001002013. The reversal of 21001001002002 is 20020010010012.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31126138 + ... + 31793685.

It is an arithmetic number, because the mean of its divisors is an integer number (834316866240).

Almost surely, 2^{21001001002002} is an apocalyptic number.

21001001002002 is an abundant number, since it is smaller than the sum of its proper divisors (32395278437358).

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

21001001002002 is a wasteful number, since it uses less digits than its factorization.

21001001002002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62920724 (or 62920718 counting only the distinct ones).

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

Adding to 21001001002002 its reverse (20020010010012), we get a palindrome (41021011012014).

The spelling of 21001001002002 in words is "twenty-one trillion, one billion, one million, two thousand, two".