9405568661 has 2 divisors, whose sum is σ = 9405568662. Its totient is φ = 9405568660.

The previous prime is 9405568639. The next prime is 9405568663. The reversal of 9405568661 is 1668655049.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7529032900 + 1876535761 = 86770^2 + 43319^2 .

It is a cyclic number.

It is not a de Polignac number, because 9405568661 - 2¹⁸ = 9405306517 is a prime.

Together with 9405568663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9405568663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4702784330 + 4702784331.

It is an arithmetic number, because the mean of its divisors is an integer number (4702784331).

Almost surely, 2^9405568661 is an apocalyptic number.

It is an amenable number.

9405568661 is a deficient number, since it is larger than the sum of its proper divisors (1).

9405568661 is an equidigital number, since it uses as much as digits as its factorization.

9405568661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The square root of 9405568661 is about 96982.3110726900. The cubic root of 9405568661 is about 2110.8709641545.

The spelling of 9405568661 in words is "nine billion, four hundred five million, five hundred sixty-eight thousand, six hundred sixty-one".