21201021210111 has 4 divisors (see below), whose sum is σ = 28268028280152. Its totient is φ = 14134014140072.

The previous prime is 21201021210107. The next prime is 21201021210119. The reversal of 21201021210111 is 11101212010212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21201021210111 - 2² = 21201021210107 is a prime.

It is a super-3 number, since 3×21201021210111³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201021210119) 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, 3533503535016 + ... + 3533503535021.

It is an arithmetic number, because the mean of its divisors is an integer number (7067007070038).

Almost surely, 2^{21201021210111} is an apocalyptic number.

21201021210111 is a deficient number, since it is larger than the sum of its proper divisors (7067007070041).

21201021210111 is an equidigital number, since it uses as much as digits as its factorization.

21201021210111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7067007070040.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21201021210111 its reverse (11101212010212), we get a palindrome (32302233220323).

The spelling of 21201021210111 in words is "twenty-one trillion, two hundred one billion, twenty-one million, two hundred ten thousand, one hundred eleven".