9725349721 has 4 divisors (see below), whose sum is σ = 9727958692. Its totient is φ = 9722740752.

The previous prime is 9725349679. The next prime is 9725349727. The reversal of 9725349721 is 1279435279.

It is a happy number.

9725349721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6506035600 + 3219314121 = 80660^2 + 56739^2 .

It is a cyclic number.

It is not a de Polignac number, because 9725349721 - 2⁷ = 9725349593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9725349727) 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 in 3 ways as a sum of consecutive naturals, for example, 1298886 + ... + 1306351.

It is an arithmetic number, because the mean of its divisors is an integer number (2431989673).

Almost surely, 2^9725349721 is an apocalyptic number.

It is an amenable number.

9725349721 is a deficient number, since it is larger than the sum of its proper divisors (2608971).

9725349721 is a wasteful number, since it uses less digits than its factorization.

9725349721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2608970.

The product of its digits is 952560, while the sum is 49.

The square root of 9725349721 is about 98617.1877564961. The cubic root of 9725349721 is about 2134.5274414781.

The spelling of 9725349721 in words is "nine billion, seven hundred twenty-five million, three hundred forty-nine thousand, seven hundred twenty-one".