21002112001 has 16 divisors (see below), whose sum is σ = 24251270400. Its totient is φ = 18015199488.

The previous prime is 21002111993. The next prime is 21002112017. The reversal of 21002112001 is 10021120012.

It is not a de Polignac number, because 21002112001 - 2³ = 21002111993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002112101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 584011 + ... + 618928.

It is an arithmetic number, because the mean of its divisors is an integer number (1515704400).

Almost surely, 2^21002112001 is an apocalyptic number.

It is an amenable number.

21002112001 is a deficient number, since it is larger than the sum of its proper divisors (3249158399).

21002112001 is a wasteful number, since it uses less digits than its factorization.

21002112001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1203048.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21002112001 its reverse (10021120012), we get a palindrome (31023232013).

It can be divided in two parts, 2 and 1002112001, that multiplied together give a palindrome (2004224002).

The spelling of 21002112001 in words is "twenty-one billion, two million, one hundred twelve thousand, one".