9565555661 has 2 divisors, whose sum is σ = 9565555662. Its totient is φ = 9565555660.

The previous prime is 9565555639. The next prime is 9565555687. The reversal of 9565555661 is 1665555659.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9011894761 + 553660900 = 94931^2 + 23530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9565555661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9565575661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4782777830 + 4782777831.

It is an arithmetic number, because the mean of its divisors is an integer number (4782777831).

Almost surely, 2^9565555661 is an apocalyptic number.

It is an amenable number.

9565555661 is a deficient number, since it is larger than the sum of its proper divisors (1).

9565555661 is an equidigital number, since it uses as much as digits as its factorization.

9565555661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6075000, while the sum is 53.

The square root of 9565555661 is about 97803.6587301314. The cubic root of 9565555661 is about 2122.7722470071.

The spelling of 9565555661 in words is "nine billion, five hundred sixty-five million, five hundred fifty-five thousand, six hundred sixty-one".