20221211809 has 2 divisors, whose sum is σ = 20221211810. Its totient is φ = 20221211808.

The previous prime is 20221211749. The next prime is 20221211821. The reversal of 20221211809 is 90811212202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17803031184 + 2418180625 = 133428^2 + 49175^2 .

It is a cyclic number.

It is not a de Polignac number, because 20221211809 - 2¹¹ = 20221209761 is a prime.

It is not a weakly prime, because it can be changed into another prime (20221211209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10110605904 + 10110605905.

It is an arithmetic number, because the mean of its divisors is an integer number (10110605905).

Almost surely, 2^20221211809 is an apocalyptic number.

It is an amenable number.

20221211809 is a deficient number, since it is larger than the sum of its proper divisors (1).

20221211809 is an equidigital number, since it uses as much as digits as its factorization.

20221211809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 28.

The spelling of 20221211809 in words is "twenty billion, two hundred twenty-one million, two hundred eleven thousand, eight hundred nine".