221020011209 has 2 divisors, whose sum is σ = 221020011210. Its totient is φ = 221020011208.

The previous prime is 221020011203. The next prime is 221020011217. The reversal of 221020011209 is 902110020122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 217718359609 + 3301651600 = 466603^2 + 57460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221020011209 is a prime.

It is not a weakly prime, because it can be changed into another prime (221020011203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510005604 + 110510005605.

It is an arithmetic number, because the mean of its divisors is an integer number (110510005605).

Almost surely, 2^221020011209 is an apocalyptic number.

It is an amenable number.

221020011209 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020011209 is an equidigital number, since it uses as much as digits as its factorization.

221020011209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 221020011209 in words is "two hundred twenty-one billion, twenty million, eleven thousand, two hundred nine".