21001020000012 has 60 divisors (see below), whose sum is σ = 59123954228416. Its totient is φ = 6461852306400.

The previous prime is 21001019999987. The next prime is 21001020000017. The reversal of 21001020000012 is 21000002010012.

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

It is a junction number, because it is equal to n+sod(n) for n = 21001019999949 and 21001020000003.

It is not an unprimeable number, because it can be changed into a prime (21001020000017) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2492994364 + ... + 2493002787.

Almost surely, 2^{21001020000012} is an apocalyptic number.

It is an amenable number.

21001020000012 is an abundant number, since it is smaller than the sum of its proper divisors (38122934228404).

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

21001020000012 is a wasteful number, since it uses less digits than its factorization.

21001020000012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4985997180 (or 4985997169 counting only the distinct ones).

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

Adding to 21001020000012 its reverse (21000002010012), we get a palindrome (42001022010024).

The spelling of 21001020000012 in words is "twenty-one trillion, one billion, twenty million, twelve", and thus it is an aban number and an uban number.