221021220109609 has 2 divisors, whose sum is σ = 221021220109610. Its totient is φ = 221021220109608.

The previous prime is 221021220109589. The next prime is 221021220109633. The reversal of 221021220109609 is 906901022120122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171811065259584 + 49210154850025 = 13107672^2 + 7014995^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021220109609 - 2¹¹ = 221021220107561 is a prime.

It is not a weakly prime, because it can be changed into another prime (221021220109309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510610054804 + 110510610054805.

It is an arithmetic number, because the mean of its divisors is an integer number (110510610054805).

Almost surely, 2^{221021220109609} is an apocalyptic number.

It is an amenable number.

221021220109609 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021220109609 is an equidigital number, since it uses as much as digits as its factorization.

221021220109609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The spelling of 221021220109609 in words is "two hundred twenty-one trillion, twenty-one billion, two hundred twenty million, one hundred nine thousand, six hundred nine".