9655721 has 2 divisors, whose sum is σ = 9655722. Its totient is φ = 9655720.

The previous prime is 9655717. The next prime is 9655729. The reversal of 9655721 is 1275569.

9655721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8065600 + 1590121 = 2840^2 + 1261^2 .

It is an emirp because it is prime and its reverse (1275569) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9655721 - 2² = 9655717 is a prime.

It is not a weakly prime, because it can be changed into another prime (9655729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4827860 + 4827861.

It is an arithmetic number, because the mean of its divisors is an integer number (4827861).

Almost surely, 2^9655721 is an apocalyptic number.

It is an amenable number.

9655721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9655721 is an equidigital number, since it uses as much as digits as its factorization.

9655721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18900, while the sum is 35.

The square root of 9655721 is about 3107.3656044952. The cubic root of 9655721 is about 212.9421180346.

The spelling of 9655721 in words is "nine million, six hundred fifty-five thousand, seven hundred twenty-one".