660801919 has 2 divisors, whose sum is σ = 660801920. Its totient is φ = 660801918.

The previous prime is 660801863. The next prime is 660801943. The reversal of 660801919 is 919108066.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 660801919 - 2¹¹ = 660799871 is a prime.

It is a super-2 number, since 2×660801919² = 873318352308165122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660801319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330400959 + 330400960.

It is an arithmetic number, because the mean of its divisors is an integer number (330400960).

Almost surely, 2^660801919 is an apocalyptic number.

660801919 is a deficient number, since it is larger than the sum of its proper divisors (1).

660801919 is an equidigital number, since it uses as much as digits as its factorization.

660801919 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 40.

The square root of 660801919 is about 25706.0677467403. The cubic root of 660801919 is about 871.0112515534.

The spelling of 660801919 in words is "six hundred sixty million, eight hundred one thousand, nine hundred nineteen".