660844157 has 2 divisors, whose sum is σ = 660844158. Its totient is φ = 660844156.

The previous prime is 660844139. The next prime is 660844181. The reversal of 660844157 is 751448066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 387735481 + 273108676 = 19691^2 + 16526^2 .

It is a cyclic number.

It is not a de Polignac number, because 660844157 - 2⁸ = 660843901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660844057) 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, 330422078 + 330422079.

It is an arithmetic number, because the mean of its divisors is an integer number (330422079).

Almost surely, 2^660844157 is an apocalyptic number.

It is an amenable number.

660844157 is a deficient number, since it is larger than the sum of its proper divisors (1).

660844157 is an equidigital number, since it uses as much as digits as its factorization.

660844157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 660844157 is about 25706.8892906162. The cubic root of 660844157 is about 871.0298093029.

The spelling of 660844157 in words is "six hundred sixty million, eight hundred forty-four thousand, one hundred fifty-seven".