9721565701 has 2 divisors, whose sum is σ = 9721565702. Its totient is φ = 9721565700.

The previous prime is 9721565677. The next prime is 9721565723. The reversal of 9721565701 is 1075651279.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9438316801 + 283248900 = 97151^2 + 16830^2 .

It is a cyclic number.

It is not a de Polignac number, because 9721565701 - 2⁷ = 9721565573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9721565771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4860782850 + 4860782851.

It is an arithmetic number, because the mean of its divisors is an integer number (4860782851).

Almost surely, 2^9721565701 is an apocalyptic number.

It is an amenable number.

9721565701 is a deficient number, since it is larger than the sum of its proper divisors (1).

9721565701 is an equidigital number, since it uses as much as digits as its factorization.

9721565701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 132300, while the sum is 43.

The square root of 9721565701 is about 98598.0004918964. Note that the first 3 decimals coincide. The cubic root of 9721565701 is about 2134.2505656654.

The spelling of 9721565701 in words is "nine billion, seven hundred twenty-one million, five hundred sixty-five thousand, seven hundred one".