688037680 has 40 divisors (see below), whose sum is σ = 1745115984. Its totient is φ = 250195200.

The previous prime is 688037659. The next prime is 688037759. The reversal of 688037680 is 86730886.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 688037680.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 390051 + ... + 391810.

Almost surely, 2^688037680 is an apocalyptic number.

It is an amenable number.

688037680 is an abundant number, since it is smaller than the sum of its proper divisors (1057078304).

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

688037680 is a wasteful number, since it uses less digits than its factorization.

688037680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 781885 (or 781879 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 46.

The square root of 688037680 is about 26230.4723556401. The cubic root of 688037680 is about 882.8171084449.

The spelling of 688037680 in words is "six hundred eighty-eight million, thirty-seven thousand, six hundred eighty".