21112012001 has 4 divisors (see below), whose sum is σ = 21112313604. Its totient is φ = 21111710400.

The previous prime is 21112011917. The next prime is 21112012049. The reversal of 21112012001 is 10021021112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 12978677776 + 8133334225 = 113924^2 + 90185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112012001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112018001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14861 + ... + 206021.

It is an arithmetic number, because the mean of its divisors is an integer number (5278078401).

Almost surely, 2^21112012001 is an apocalyptic number.

It is an amenable number.

21112012001 is a deficient number, since it is larger than the sum of its proper divisors (301603).

21112012001 is a wasteful number, since it uses less digits than its factorization.

21112012001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301602.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21112012001 its reverse (10021021112), we get a palindrome (31133033113).

The spelling of 21112012001 in words is "twenty-one billion, one hundred twelve million, twelve thousand, one".