688639612 has 12 divisors (see below), whose sum is σ = 1205464680. Its totient is φ = 344221136.

The previous prime is 688639607. The next prime is 688639639. The reversal of 688639612 is 216936886.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7663 + ... + 37894.

It is an arithmetic number, because the mean of its divisors is an integer number (100455390).

Almost surely, 2^688639612 is an apocalyptic number.

It is an amenable number.

688639612 is a deficient number, since it is larger than the sum of its proper divisors (516825068).

688639612 is a wasteful number, since it uses less digits than its factorization.

688639612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49340 (or 49338 counting only the distinct ones).

The product of its digits is 746496, while the sum is 49.

The square root of 688639612 is about 26241.9437542267. The cubic root of 688639612 is about 883.0744785444.

The spelling of 688639612 in words is "six hundred eighty-eight million, six hundred thirty-nine thousand, six hundred twelve".