660065993 has 2 divisors, whose sum is σ = 660065994. Its totient is φ = 660065992.

The previous prime is 660065971. The next prime is 660066037. The reversal of 660065993 is 399560066.

It is an a-pointer prime, because the next prime (660066037) can be obtained adding 660065993 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 468852409 + 191213584 = 21653^2 + 13828^2 .

It is a cyclic number.

It is not a de Polignac number, because 660065993 - 2⁸ = 660065737 is a prime.

It is not a weakly prime, because it can be changed into another prime (660565993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330032996 + 330032997.

It is an arithmetic number, because the mean of its divisors is an integer number (330032997).

Almost surely, 2^660065993 is an apocalyptic number.

It is an amenable number.

660065993 is a deficient number, since it is larger than the sum of its proper divisors (1).

660065993 is an equidigital number, since it uses as much as digits as its factorization.

660065993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 262440, while the sum is 44.

The square root of 660065993 is about 25691.7495122461. The cubic root of 660065993 is about 870.6877870311.

The spelling of 660065993 in words is "six hundred sixty million, sixty-five thousand, nine hundred ninety-three".