688720065 has 32 divisors (see below), whose sum is σ = 1272848256. Its totient is φ = 314280960.

The previous prime is 688720063. The next prime is 688720069. The reversal of 688720065 is 560027886.

It is not a de Polignac number, because 688720065 - 2¹ = 688720063 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 688719999 and 688720026.

It is not an unprimeable number, because it can be changed into a prime (688720063) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 119962 + ... + 125571.

It is an arithmetic number, because the mean of its divisors is an integer number (39776508).

Almost surely, 2^688720065 is an apocalyptic number.

It is an amenable number.

688720065 is a deficient number, since it is larger than the sum of its proper divisors (584128191).

688720065 is a wasteful number, since it uses less digits than its factorization.

688720065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245569.

The product of its (nonzero) digits is 161280, while the sum is 42.

The square root of 688720065 is about 26243.4766180093. The cubic root of 688720065 is about 883.1088667417.

The spelling of 688720065 in words is "six hundred eighty-eight million, seven hundred twenty thousand, sixty-five".