21201220210111 has 16 divisors (see below), whose sum is σ = 22767251061600. Its totient is φ = 19682655177600.

The previous prime is 21201220210109. The next prime is 21201220210117. The reversal of 21201220210111 is 11101202210212.

It is a cyclic number.

It is not a de Polignac number, because 21201220210111 - 2¹ = 21201220210109 is a prime.

It is a super-2 number, since 2×21201220210111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201220210117) 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 15 ways as a sum of consecutive naturals, for example, 33689500 + ... + 34313041.

It is an arithmetic number, because the mean of its divisors is an integer number (1422953191350).

Almost surely, 2^{21201220210111} is an apocalyptic number.

21201220210111 is a deficient number, since it is larger than the sum of its proper divisors (1566030851489).

21201220210111 is a wasteful number, since it uses less digits than its factorization.

21201220210111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68002890.

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

Adding to 21201220210111 its reverse (11101202210212), we get a palindrome (32302422420323).

The spelling of 21201220210111 in words is "twenty-one trillion, two hundred one billion, two hundred twenty million, two hundred ten thousand, one hundred eleven".