21001111111101 has 8 divisors (see below), whose sum is σ = 30547070707104. Its totient is φ = 12727946127920.

The previous prime is 21001111111081. The next prime is 21001111111103. The reversal of 21001111111101 is 10111111110012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21001111111101 - 2⁹ = 21001111110589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001111111103) 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 7 ways as a sum of consecutive naturals, for example, 318198653166 + ... + 318198653231.

It is an arithmetic number, because the mean of its divisors is an integer number (3818383838388).

Almost surely, 2^{21001111111101} is an apocalyptic number.

It is an amenable number.

21001111111101 is a deficient number, since it is larger than the sum of its proper divisors (9545959596003).

21001111111101 is a wasteful number, since it uses less digits than its factorization.

21001111111101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636397306411.

The product of its (nonzero) digits is 2, while the sum is 12.

Adding to 21001111111101 its reverse (10111111110012), we get a palindrome (31112222221113).

The spelling of 21001111111101 in words is "twenty-one trillion, one billion, one hundred eleven million, one hundred eleven thousand, one hundred one".