21201200000111 has 4 divisors (see below), whose sum is σ = 21312201047424. Its totient is φ = 21090198952800.

The previous prime is 21201200000089. The next prime is 21201200000129. The reversal of 21201200000111 is 11100000210212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201200000111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201200000092 and 21201200000101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201200000161) 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, 55500523370 + ... + 55500523751.

It is an arithmetic number, because the mean of its divisors is an integer number (5328050261856).

Almost surely, 2^{21201200000111} is an apocalyptic number.

21201200000111 is a deficient number, since it is larger than the sum of its proper divisors (111001047313).

21201200000111 is a wasteful number, since it uses less digits than its factorization.

21201200000111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111001047312.

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

Adding to 21201200000111 its reverse (11100000210212), we get a palindrome (32301200210323).

The spelling of 21201200000111 in words is "twenty-one trillion, two hundred one billion, two hundred million, one hundred eleven", and thus it is an aban number.