21111201222001 has 4 divisors (see below), whose sum is σ = 23030401333104. Its totient is φ = 19192001110900.

The previous prime is 21111201221989. The next prime is 21111201222031. The reversal of 21111201222001 is 10022210211112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111201222001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21111201222031) 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 3 ways as a sum of consecutive naturals, for example, 959600055535 + ... + 959600055556.

It is an arithmetic number, because the mean of its divisors is an integer number (5757600333276).

Almost surely, 2^{21111201222001} is an apocalyptic number.

It is an amenable number.

21111201222001 is a deficient number, since it is larger than the sum of its proper divisors (1919200111103).

21111201222001 is a wasteful number, since it uses less digits than its factorization.

21111201222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919200111102.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21111201222001 its reverse (10022210211112), we get a palindrome (31133411433113).

The spelling of 21111201222001 in words is "twenty-one trillion, one hundred eleven billion, two hundred one million, two hundred twenty-two thousand, one".