21020012102001 has 24 divisors (see below), whose sum is σ = 30806706058912. Its totient is φ = 12739187260800.

The previous prime is 21020012101889. The next prime is 21020012102059. The reversal of 21020012102001 is 10020121002012.

It is not a de Polignac number, because 21020012102001 - 2²³ = 21020003713393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020012102071) 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, 22667466 + ... + 23576556.

Almost surely, 2^{21020012102001} is an apocalyptic number.

It is an amenable number.

21020012102001 is a deficient number, since it is larger than the sum of its proper divisors (9786693956911).

21020012102001 is a wasteful number, since it uses less digits than its factorization.

21020012102001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972813 (or 972802 counting only the distinct ones).

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

Adding to 21020012102001 its reverse (10020121002012), we get a palindrome (31040133104013).

The spelling of 21020012102001 in words is "twenty-one trillion, twenty billion, twelve million, one hundred two thousand, one".