21111211000001 has 4 divisors (see below), whose sum is σ = 21112974836100. Its totient is φ = 21109447163904.

The previous prime is 21111210999821. The next prime is 21111211000039. The reversal of 21111211000001 is 10000011211112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3581749287601 + 17529461712400 = 1892551^2 + 4186820^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111211000001 - 2²⁶ = 21111143891137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111211009001) 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, 881900096 + ... + 881924033.

It is an arithmetic number, because the mean of its divisors is an integer number (5278243709025).

Almost surely, 2^{21111211000001} is an apocalyptic number.

It is an amenable number.

21111211000001 is a deficient number, since it is larger than the sum of its proper divisors (1763836099).

21111211000001 is a wasteful number, since it uses less digits than its factorization.

21111211000001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1763836098.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 21111211000001 its reverse (10000011211112), we get a palindrome (31111222211113).

The spelling of 21111211000001 in words is "twenty-one trillion, one hundred eleven billion, two hundred eleven million, one", and thus it is an aban number.