221220022220021 has 4 divisors (see below), whose sum is σ = 241330933330944. Its totient is φ = 201109111109100.

The previous prime is 221220022219991. The next prime is 221220022220039. The reversal of 221220022220021 is 120022220022122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221220022220021 - 2²² = 221220018025717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221220022219975 and 221220022220002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220022220221) 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, 10055455555445 + ... + 10055455555466.

It is an arithmetic number, because the mean of its divisors is an integer number (60332733332736).

Almost surely, 2^{221220022220021} is an apocalyptic number.

It is an amenable number.

221220022220021 is a deficient number, since it is larger than the sum of its proper divisors (20110911110923).

221220022220021 is a wasteful number, since it uses less digits than its factorization.

221220022220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20110911110922.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 221220022220021 its reverse (120022220022122), we get a palindrome (341242242242143).

The spelling of 221220022220021 in words is "two hundred twenty-one trillion, two hundred twenty billion, twenty-two million, two hundred twenty thousand, twenty-one".