221020121311 has 4 divisors (see below), whose sum is σ = 241112859624. Its totient is φ = 200927383000.

The previous prime is 221020121279. The next prime is 221020121317. The reversal of 221020121311 is 113121020122.

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 221020121311 - 2⁵ = 221020121279 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 (221020121317) 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, 10046369140 + ... + 10046369161.

It is an arithmetic number, because the mean of its divisors is an integer number (60278214906).

Almost surely, 2^221020121311 is an apocalyptic number.

221020121311 is a deficient number, since it is larger than the sum of its proper divisors (20092738313).

221020121311 is a wasteful number, since it uses less digits than its factorization.

221020121311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20092738312.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 221020121311 its reverse (113121020122), we get a palindrome (334141141433).

The spelling of 221020121311 in words is "two hundred twenty-one billion, twenty million, one hundred twenty-one thousand, three hundred eleven".