660616291 has 2 divisors, whose sum is σ = 660616292. Its totient is φ = 660616290.

The previous prime is 660616289. The next prime is 660616321. The reversal of 660616291 is 192616066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660616291 - 2¹ = 660616289 is a prime.

It is a super-3 number, since 3×660616291³ (a number of 27 digits) contains 333 as substring.

Together with 660616289, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 660616291.

It is not a weakly prime, because it can be changed into another prime (660611291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330308145 + 330308146.

It is an arithmetic number, because the mean of its divisors is an integer number (330308146).

Almost surely, 2^660616291 is an apocalyptic number.

660616291 is a deficient number, since it is larger than the sum of its proper divisors (1).

660616291 is an equidigital number, since it uses as much as digits as its factorization.

660616291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 660616291 is about 25702.4569059069. The cubic root of 660616291 is about 870.9296843878.

The spelling of 660616291 in words is "six hundred sixty million, six hundred sixteen thousand, two hundred ninety-one".