221101211021 has 2 divisors, whose sum is σ = 221101211022. Its totient is φ = 221101211020.

The previous prime is 221101210987. The next prime is 221101211029. The reversal of 221101211021 is 120112101122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 220481898025 + 619312996 = 469555^2 + 24886^2 .

It is a cyclic number.

It is not a de Polignac number, because 221101211021 - 2¹⁰ = 221101209997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221101210987 and 221101211005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221101211029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110550605510 + 110550605511.

It is an arithmetic number, because the mean of its divisors is an integer number (110550605511).

Almost surely, 2^221101211021 is an apocalyptic number.

It is an amenable number.

221101211021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221101211021 is an equidigital number, since it uses as much as digits as its factorization.

221101211021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 221101211021 its reverse (120112101122), we get a palindrome (341213312143).

The spelling of 221101211021 in words is "two hundred twenty-one billion, one hundred one million, two hundred eleven thousand, twenty-one".