221020021122101 has 4 divisors (see below), whose sum is σ = 221021638687500. Its totient is φ = 221018403556704.

The previous prime is 221020021122079. The next prime is 221020021122137. The reversal of 221020021122101 is 101221120020122.

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

It can be written as a sum of positive squares in 2 ways, for example, as 201357660903025 + 19662360219076 = 14190055^2 + 4434226^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221020021122101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221020021122101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221020021122151) 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, 808577726 + ... + 808851023.

It is an arithmetic number, because the mean of its divisors is an integer number (55255409671875).

Almost surely, 2^{221020021122101} is an apocalyptic number.

It is an amenable number.

221020021122101 is a deficient number, since it is larger than the sum of its proper divisors (1617565399).

221020021122101 is a wasteful number, since it uses less digits than its factorization.

221020021122101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1617565398.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221020021122101 its reverse (101221120020122), we get a palindrome (322241141142223).

The spelling of 221020021122101 in words is "two hundred twenty-one trillion, twenty billion, twenty-one million, one hundred twenty-two thousand, one hundred one".