21000000010002 has 64 divisors (see below), whose sum is σ = 45358048654464. Its totient is φ = 6443365294080.

The previous prime is 21000000009971. The next prime is 21000000010007. The reversal of 21000000010002 is 20001000000012.

It is a happy number.

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

It is not an unprimeable number, because it can be changed into a prime (21000000010007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 106951377 + ... + 107147547.

It is an arithmetic number, because the mean of its divisors is an integer number (708719510226).

Almost surely, 2^{21000000010002} is an apocalyptic number.

21000000010002 is an abundant number, since it is smaller than the sum of its proper divisors (24358048644462).

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

21000000010002 is a wasteful number, since it uses less digits than its factorization.

21000000010002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200043.

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

Adding to 21000000010002 its reverse (20001000000012), we get a palindrome (41001000010014).

The spelling of 21000000010002 in words is "twenty-one trillion, ten thousand, two".