687903387649 has 2 divisors, whose sum is σ = 687903387650. Its totient is φ = 687903387648.

The previous prime is 687903387641. The next prime is 687903387673. The reversal of 687903387649 is 946783309786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 670105960000 + 17797427649 = 818600^2 + 133407^2 .

It is a cyclic number.

It is not a de Polignac number, because 687903387649 - 2³ = 687903387641 is a prime.

It is a super-2 number, since 2×687903387649² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (687903387641) 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, 343951693824 + 343951693825.

It is an arithmetic number, because the mean of its divisors is an integer number (343951693825).

Almost surely, 2^687903387649 is an apocalyptic number.

It is an amenable number.

687903387649 is a deficient number, since it is larger than the sum of its proper divisors (1).

687903387649 is an equidigital number, since it uses as much as digits as its factorization.

687903387649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 329204736, while the sum is 70.

The spelling of 687903387649 in words is "six hundred eighty-seven billion, nine hundred three million, three hundred eighty-seven thousand, six hundred forty-nine".