221011216021 has 2 divisors, whose sum is σ = 221011216022. Its totient is φ = 221011216020.

The previous prime is 221011216007. The next prime is 221011216031. The reversal of 221011216021 is 120612110122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202491000100 + 18520215921 = 449990^2 + 136089^2 .

It is a cyclic number.

It is not a de Polignac number, because 221011216021 - 2²⁹ = 220474345109 is a prime.

It is a super-2 number, since 2×221011216021² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221011216021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221011216031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110505608010 + 110505608011.

It is an arithmetic number, because the mean of its divisors is an integer number (110505608011).

Almost surely, 2^221011216021 is an apocalyptic number.

It is an amenable number.

221011216021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221011216021 is an equidigital number, since it uses as much as digits as its factorization.

221011216021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 221011216021 its reverse (120612110122), we get a palindrome (341623326143).

The spelling of 221011216021 in words is "two hundred twenty-one billion, eleven million, two hundred sixteen thousand, twenty-one".