209182730121 has 10 divisors (see below), whose sum is σ = 312482843882. Its totient is φ = 139455153360.

The previous prime is 209182730111. The next prime is 209182730129. The reversal of 209182730121 is 121037281902.

It can be written as a sum of positive squares in only one way, i.e., 193656324096 + 15526406025 = 440064^2 + 124605^2 .

It is not a de Polignac number, because 209182730121 - 2¹⁷ = 209182599049 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (209182730129) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1291251340 + ... + 1291251501.

Almost surely, 2^209182730121 is an apocalyptic number.

It is an amenable number.

209182730121 is a deficient number, since it is larger than the sum of its proper divisors (103300113761).

209182730121 is an equidigital number, since it uses as much as digits as its factorization.

209182730121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2582502853 (or 2582502844 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The spelling of 209182730121 in words is "two hundred nine billion, one hundred eighty-two million, seven hundred thirty thousand, one hundred twenty-one".