66325661 has 2 divisors, whose sum is σ = 66325662. Its totient is φ = 66325660.

The previous prime is 66325643. The next prime is 66325663. The reversal of 66325661 is 16652366.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59382436 + 6943225 = 7706^2 + 2635^2 .

It is a cyclic number.

It is not a de Polignac number, because 66325661 - 2¹⁴ = 66309277 is a prime.

Together with 66325663, 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 (66325663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33162830 + 33162831.

It is an arithmetic number, because the mean of its divisors is an integer number (33162831).

Almost surely, 2^66325661 is an apocalyptic number.

It is an amenable number.

66325661 is a deficient number, since it is larger than the sum of its proper divisors (1).

66325661 is an equidigital number, since it uses as much as digits as its factorization.

66325661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 35.

The square root of 66325661 is about 8144.0567900770. The cubic root of 66325661 is about 404.7875957815.

The spelling of 66325661 in words is "sixty-six million, three hundred twenty-five thousand, six hundred sixty-one".