221002220021 has 4 divisors (see below), whose sum is σ = 241093330944. Its totient is φ = 200911109100.

The previous prime is 221002219987. The next prime is 221002220051. The reversal of 221002220021 is 120022200122.

221002220021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a de Polignac number, because none of the positive numbers 2^k-221002220021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221002219978 and 221002220005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221002220051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10045555445 + ... + 10045555466.

It is an arithmetic number, because the mean of its divisors is an integer number (60273332736).

Almost surely, 2^221002220021 is an apocalyptic number.

It is an amenable number.

221002220021 is a deficient number, since it is larger than the sum of its proper divisors (20091110923).

221002220021 is a wasteful number, since it uses less digits than its factorization.

221002220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20091110922.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 221002220021 its reverse (120022200122), we get a palindrome (341024420143).

The spelling of 221002220021 in words is "two hundred twenty-one billion, two million, two hundred twenty thousand, twenty-one".