688397994 has 32 divisors (see below), whose sum is σ = 1535450880. Its totient is φ = 228614400.

The previous prime is 688397989. The next prime is 688398041. The reversal of 688397994 is 499793886.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8887 + ... + 38154.

It is an arithmetic number, because the mean of its divisors is an integer number (47982840).

Almost surely, 2^688397994 is an apocalyptic number.

688397994 is an abundant number, since it is smaller than the sum of its proper divisors (847052886).

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

688397994 is a wasteful number, since it uses less digits than its factorization.

688397994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47323 (or 47317 counting only the distinct ones).

The product of its digits is 23514624, while the sum is 63.

The square root of 688397994 is about 26237.3396898390. The cubic root of 688397994 is about 882.9711871447.

The spelling of 688397994 in words is "six hundred eighty-eight million, three hundred ninety-seven thousand, nine hundred ninety-four".