688690773 has 6 divisors (see below), whose sum is σ = 994775574. Its totient is φ = 459127176.

The previous prime is 688690763. The next prime is 688690813. The reversal of 688690773 is 377096886.

It can be written as a sum of positive squares in only one way, i.e., 632170449 + 56520324 = 25143^2 + 7518^2 .

It is not a de Polignac number, because 688690773 - 2⁵ = 688690741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688690703) 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 in 5 ways as a sum of consecutive naturals, for example, 38260590 + ... + 38260607.

It is an arithmetic number, because the mean of its divisors is an integer number (165795929).

Almost surely, 2^688690773 is an apocalyptic number.

It is an amenable number.

688690773 is a deficient number, since it is larger than the sum of its proper divisors (306084801).

688690773 is a wasteful number, since it uses less digits than its factorization.

688690773 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76521203 (or 76521200 counting only the distinct ones).

The product of its (nonzero) digits is 3048192, while the sum is 54.

The square root of 688690773 is about 26242.9185305293. The cubic root of 688690773 is about 883.0963467097.

The spelling of 688690773 in words is "six hundred eighty-eight million, six hundred ninety thousand, seven hundred seventy-three".