201221111011 has 16 divisors (see below), whose sum is σ = 216822878208. Its totient is φ = 186195002400.

The previous prime is 201221110969. The next prime is 201221111033. The reversal of 201221111011 is 110111122102.

It is a happy number.

It is not a de Polignac number, because 201221111011 - 2²¹ = 201219013859 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201221110982 and 201221111000.

It is not an unprimeable number, because it can be changed into a prime (201221111041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1939425 + ... + 2040541.

It is an arithmetic number, because the mean of its divisors is an integer number (13551429888).

Almost surely, 2^201221111011 is an apocalyptic number.

201221111011 is a deficient number, since it is larger than the sum of its proper divisors (15601767197).

201221111011 is a wasteful number, since it uses less digits than its factorization.

201221111011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103962.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 201221111011 its reverse (110111122102), we get a palindrome (311332233113).

The spelling of 201221111011 in words is "two hundred one billion, two hundred twenty-one million, one hundred eleven thousand, eleven".