21223199609 has 2 divisors, whose sum is σ = 21223199610. Its totient is φ = 21223199608.

The previous prime is 21223199597. The next prime is 21223199617. The reversal of 21223199609 is 90699132212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17655765625 + 3567433984 = 132875^2 + 59728^2 .

It is a cyclic number.

It is not a de Polignac number, because 21223199609 - 2³² = 16928232313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21223199609.

It is not a weakly prime, because it can be changed into another prime (21223199689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611599804 + 10611599805.

It is an arithmetic number, because the mean of its divisors is an integer number (10611599805).

Almost surely, 2^21223199609 is an apocalyptic number.

It is an amenable number.

21223199609 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223199609 is an equidigital number, since it uses as much as digits as its factorization.

21223199609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 44.

The spelling of 21223199609 in words is "twenty-one billion, two hundred twenty-three million, one hundred ninety-nine thousand, six hundred nine".