9209037666821 has 2 divisors, whose sum is σ = 9209037666822. Its totient is φ = 9209037666820.

The previous prime is 9209037666811. The next prime is 9209037666863. The reversal of 9209037666821 is 1286667309029.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6874039741921 + 2334997924900 = 2621839^2 + 1528070^2 .

It is a cyclic number.

It is not a de Polignac number, because 9209037666821 - 2³⁴ = 9191857797637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9209037666811) 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 as a sum of consecutive naturals, namely, 4604518833410 + 4604518833411.

It is an arithmetic number, because the mean of its divisors is an integer number (4604518833411).

Almost surely, 2^{9209037666821} is an apocalyptic number.

It is an amenable number.

9209037666821 is a deficient number, since it is larger than the sum of its proper divisors (1).

9209037666821 is an equidigital number, since it uses as much as digits as its factorization.

9209037666821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11757312, while the sum is 59.

The spelling of 9209037666821 in words is "nine trillion, two hundred nine billion, thirty-seven million, six hundred sixty-six thousand, eight hundred twenty-one".