201221212021111 has 4 divisors (see below), whose sum is σ = 201312551656552. Its totient is φ = 201129872385672.

The previous prime is 201221212021073. The next prime is 201221212021117. The reversal of 201221212021111 is 111120212122102.

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 201221212021111 - 2¹¹ = 201221212019063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221212021117) 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, 45669814416 + ... + 45669818821.

It is an arithmetic number, because the mean of its divisors is an integer number (50328137914138).

Almost surely, 2^{201221212021111} is an apocalyptic number.

201221212021111 is a deficient number, since it is larger than the sum of its proper divisors (91339635441).

201221212021111 is an equidigital number, since it uses as much as digits as its factorization.

201221212021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91339635440.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 201221212021111 its reverse (111120212122102), we get a palindrome (312341424143213).

The spelling of 201221212021111 in words is "two hundred one trillion, two hundred twenty-one billion, two hundred twelve million, twenty-one thousand, one hundred eleven".