221002210021 has 4 divisors (see below), whose sum is σ = 221006468844. Its totient is φ = 220997951200.

The previous prime is 221002209947. The next prime is 221002210031. The reversal of 221002210021 is 120012200122.

It is a happy number.

221002210021 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.

It can be written as a sum of positive squares in 2 ways, for example, as 168966213025 + 52035996996 = 411055^2 + 228114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221002210021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221002209983 and 221002210010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221002210031) 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, 2050600 + ... + 2155681.

It is an arithmetic number, because the mean of its divisors is an integer number (55251617211).

Almost surely, 2^221002210021 is an apocalyptic number.

It is an amenable number.

221002210021 is a deficient number, since it is larger than the sum of its proper divisors (4258823).

221002210021 is an equidigital number, since it uses as much as digits as its factorization.

221002210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4258822.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 221002210021 its reverse (120012200122), we get a palindrome (341014410143).

The spelling of 221002210021 in words is "two hundred twenty-one billion, two million, two hundred ten thousand, twenty-one".