660503381 has 2 divisors, whose sum is σ = 660503382. Its totient is φ = 660503380.

The previous prime is 660503359. The next prime is 660503413. The reversal of 660503381 is 183305066.

It is an a-pointer prime, because the next prime (660503413) can be obtained adding 660503381 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 617075281 + 43428100 = 24841^2 + 6590^2 .

It is a cyclic number.

It is not a de Polignac number, because 660503381 - 2¹⁰ = 660502357 is a prime.

It is a super-2 number, since 2×660503381² = 872529432624862322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660503281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330251690 + 330251691.

It is an arithmetic number, because the mean of its divisors is an integer number (330251691).

Almost surely, 2^660503381 is an apocalyptic number.

It is an amenable number.

660503381 is a deficient number, since it is larger than the sum of its proper divisors (1).

660503381 is an equidigital number, since it uses as much as digits as its factorization.

660503381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 660503381 is about 25700.2603294208. The cubic root of 660503381 is about 870.8800629081.

The spelling of 660503381 in words is "six hundred sixty million, five hundred three thousand, three hundred eighty-one".