21001112112001 has 16 divisors (see below), whose sum is σ = 24336247444096. Its totient is φ = 17751060804096.

The previous prime is 21001112111977. The next prime is 21001112112007. The reversal of 21001112112001 is 10021121110012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21001112112001 - 2¹⁹ = 21001111587713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001112112007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55641291 + ... + 56017456.

It is an arithmetic number, because the mean of its divisors is an integer number (1521015465256).

Almost surely, 2^{21001112112001} is an apocalyptic number.

It is an amenable number.

21001112112001 is a deficient number, since it is larger than the sum of its proper divisors (3335135332095).

21001112112001 is a wasteful number, since it uses less digits than its factorization.

21001112112001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111659128.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21001112112001 its reverse (10021121110012), we get a palindrome (31022233222013).

The spelling of 21001112112001 in words is "twenty-one trillion, one billion, one hundred twelve million, one hundred twelve thousand, one".