688521704 has 16 divisors (see below), whose sum is σ = 1390284420. Its totient is φ = 317779200.

The previous prime is 688521703. The next prime is 688521739. The reversal of 688521704 is 407125886.

It can be written as a sum of positive squares in 2 ways, for example, as 539632900 + 148888804 = 23230^2 + 12202^2 .

It is not an unprimeable number, because it can be changed into a prime (688521703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3310097 + ... + 3310304.

Almost surely, 2^688521704 is an apocalyptic number.

It is an amenable number.

688521704 is an abundant number, since it is smaller than the sum of its proper divisors (701762716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

688521704 is a wasteful number, since it uses less digits than its factorization.

688521704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6620420 (or 6620416 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 41.

The square root of 688521704 is about 26239.6971019103. The cubic root of 688521704 is about 883.0240760374.

The spelling of 688521704 in words is "six hundred eighty-eight million, five hundred twenty-one thousand, seven hundred four".