9725843221 has 2 divisors, whose sum is σ = 9725843222. Its totient is φ = 9725843220.

The previous prime is 9725843209. The next prime is 9725843251. The reversal of 9725843221 is 1223485279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9608900625 + 116942596 = 98025^2 + 10814^2 .

It is an emirp because it is prime and its reverse (1223485279) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9725843221 - 2¹³ = 9725835029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9725843201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4862921610 + 4862921611.

It is an arithmetic number, because the mean of its divisors is an integer number (4862921611).

Almost surely, 2^9725843221 is an apocalyptic number.

It is an amenable number.

9725843221 is a deficient number, since it is larger than the sum of its proper divisors (1).

9725843221 is an equidigital number, since it uses as much as digits as its factorization.

9725843221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 43.

The square root of 9725843221 is about 98619.6898240914. The cubic root of 9725843221 is about 2134.5635454574.

The spelling of 9725843221 in words is "nine billion, seven hundred twenty-five million, eight hundred forty-three thousand, two hundred twenty-one".