20563531298209 has 9 divisors (see below), whose sum is σ = 21496579366899. Its totient is φ = 19669364956560.

The previous prime is 20563531298129. The next prime is 20563531298267. The reversal of 20563531298209 is 90289213536502.

The square root of 20563531298209 is 4534703.

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

It can be written as a sum of positive squares in only one way, i.e., 20553102803809 + 10428494400 = 4533553^2 + 102120^2 .

It is not a de Polignac number, because 20563531298209 - 2⁹ = 20563531297697 is a prime.

It is a super-2 number, since 2×20563531298209² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20563531298209.

It is not an unprimeable number, because it can be changed into a prime (20563531298809) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 104199589 + ... + 104396749.

Almost surely, 2^{20563531298209} is an apocalyptic number.

20563531298209 is the 4534703-rd square number.

20563531298209 is the 2267352-nd centered octagonal number.

It is an amenable number.

20563531298209 is a deficient number, since it is larger than the sum of its proper divisors (933048068690).

20563531298209 is an frugal number, since it uses more digits than its factorization.

20563531298209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394368 (or 197184 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 55.

The spelling of 20563531298209 in words is "twenty trillion, five hundred sixty-three billion, five hundred thirty-one million, two hundred ninety-eight thousand, two hundred nine".