688703761 has 2 divisors, whose sum is σ = 688703762. Its totient is φ = 688703760.

The previous prime is 688703713. The next prime is 688703767. The reversal of 688703761 is 167307886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 556016400 + 132687361 = 23580^2 + 11519^2 .

It is a cyclic number.

It is not a de Polignac number, because 688703761 - 2¹⁵ = 688670993 is a prime.

It is not a weakly prime, because it can be changed into another prime (688703767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344351880 + 344351881.

It is an arithmetic number, because the mean of its divisors is an integer number (344351881).

Almost surely, 2^688703761 is an apocalyptic number.

It is an amenable number.

688703761 is a deficient number, since it is larger than the sum of its proper divisors (1).

688703761 is an equidigital number, since it uses as much as digits as its factorization.

688703761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 338688, while the sum is 46.

The square root of 688703761 is about 26243.1659865954. The cubic root of 688703761 is about 883.1018981046.

The spelling of 688703761 in words is "six hundred eighty-eight million, seven hundred three thousand, seven hundred sixty-one".