687668741 has 2 divisors, whose sum is σ = 687668742. Its totient is φ = 687668740.

The previous prime is 687668699. The next prime is 687668747. The reversal of 687668741 is 147866786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 559322500 + 128346241 = 23650^2 + 11329^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687668741 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 (687668747) 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, 343834370 + 343834371.

It is an arithmetic number, because the mean of its divisors is an integer number (343834371).

Almost surely, 2^687668741 is an apocalyptic number.

It is an amenable number.

687668741 is a deficient number, since it is larger than the sum of its proper divisors (1).

687668741 is an equidigital number, since it uses as much as digits as its factorization.

687668741 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2709504, while the sum is 53.

The square root of 687668741 is about 26223.4387714502. The cubic root of 687668741 is about 882.6592857439.

The spelling of 687668741 in words is "six hundred eighty-seven million, six hundred sixty-eight thousand, seven hundred forty-one".