20221693209 has 27 divisors (see below), whose sum is σ = 29551353013. Its totient is φ = 13324989912.

The previous prime is 20221693169. The next prime is 20221693229. The reversal of 20221693209 is 90239612202.

The square root of 20221693209 is 142203.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 20221693209 - 2¹⁹ = 20221168921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20221693229) 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 26 ways as a sum of consecutive naturals, for example, 45646942 + ... + 45647384.

Almost surely, 2^20221693209 is an apocalyptic number.

20221693209 is the 142203-rd square number.

20221693209 is the 71102-nd centered octagonal number.

It is an amenable number.

20221693209 is a deficient number, since it is larger than the sum of its proper divisors (9329659804).

20221693209 is an frugal number, since it uses more digits than its factorization.

20221693209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106 (or 553 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

Multiplying 20221693209 by its sum of digits (36), we get a square (727980955524 = 853218²).

The spelling of 20221693209 in words is "twenty billion, two hundred twenty-one million, six hundred ninety-three thousand, two hundred nine".