20803172209 has 2 divisors, whose sum is σ = 20803172210. Its totient is φ = 20803172208.

The previous prime is 20803172191. The next prime is 20803172237. The reversal of 20803172209 is 90227130802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20706346609 + 96825600 = 143897^2 + 9840^2 .

It is a cyclic number.

It is not a de Polignac number, because 20803172209 - 2¹¹ = 20803170161 is a prime.

It is not a weakly prime, because it can be changed into another prime (20803172279) 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, 10401586104 + 10401586105.

It is an arithmetic number, because the mean of its divisors is an integer number (10401586105).

Almost surely, 2^20803172209 is an apocalyptic number.

It is an amenable number.

20803172209 is a deficient number, since it is larger than the sum of its proper divisors (1).

20803172209 is an equidigital number, since it uses as much as digits as its factorization.

20803172209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 34.

The spelling of 20803172209 in words is "twenty billion, eight hundred three million, one hundred seventy-two thousand, two hundred nine".