688705625 has 10 divisors (see below), whose sum is σ = 860607330. Its totient is φ = 550964000.

The previous prime is 688705613. The next prime is 688705627. The reversal of 688705625 is 526507886.

It can be written as a sum of positive squares in 5 ways, for example, as 340808521 + 347897104 = 18461^2 + 18652^2 .

It is not a de Polignac number, because 688705625 - 2¹⁶ = 688640089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688705625.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688705627) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 550340 + ... + 551589.

It is an arithmetic number, because the mean of its divisors is an integer number (86060733).

Almost surely, 2^688705625 is an apocalyptic number.

It is an amenable number.

688705625 is a deficient number, since it is larger than the sum of its proper divisors (171901705).

688705625 is an equidigital number, since it uses as much as digits as its factorization.

688705625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101949 (or 1101934 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 47.

The square root of 688705625 is about 26243.2015005792. The cubic root of 688705625 is about 883.1026948189.

The spelling of 688705625 in words is "six hundred eighty-eight million, seven hundred five thousand, six hundred twenty-five".