221220212209 has 4 divisors (see below), whose sum is σ = 223177913316. Its totient is φ = 219262511104.

The previous prime is 221220212201. The next prime is 221220212219. The reversal of 221220212209 is 902212022122.

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 67691030625 + 153529181584 = 260175^2 + 391828^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220212209 - 2³ = 221220212201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221220212201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 978850384 + ... + 978850609.

It is an arithmetic number, because the mean of its divisors is an integer number (55794478329).

Almost surely, 2^221220212209 is an apocalyptic number.

It is an amenable number.

221220212209 is a deficient number, since it is larger than the sum of its proper divisors (1957701107).

221220212209 is a wasteful number, since it uses less digits than its factorization.

221220212209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1957701106.

The product of its (nonzero) digits is 1152, while the sum is 25.

The spelling of 221220212209 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, two hundred nine".