9666551 has 2 divisors, whose sum is σ = 9666552. Its totient is φ = 9666550.

The previous prime is 9666533. The next prime is 9666563. The reversal of 9666551 is 1556669.

It is a strong prime.

It is an emirp because it is prime and its reverse (1556669) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9666551 - 2¹⁰ = 9665527 is a prime.

It is a Sophie Germain prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9666571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4833275 + 4833276.

It is an arithmetic number, because the mean of its divisors is an integer number (4833276).

Almost surely, 2^9666551 is an apocalyptic number.

9666551 is a deficient number, since it is larger than the sum of its proper divisors (1).

9666551 is an equidigital number, since it uses as much as digits as its factorization.

9666551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48600, while the sum is 38.

The square root of 9666551 is about 3109.1077498215. The cubic root of 9666551 is about 213.0217013016.

The spelling of 9666551 in words is "nine million, six hundred sixty-six thousand, five hundred fifty-one".