688631438 has 16 divisors (see below), whose sum is σ = 1148114736. Its totient is φ = 307107840.

The previous prime is 688631429. The next prime is 688631443. The reversal of 688631438 is 834136886.

688631438 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 688631392 and 688631401.

It is a congruent number.

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, 294131 + ... + 296462.

It is an arithmetic number, because the mean of its divisors is an integer number (71757171).

Almost surely, 2^688631438 is an apocalyptic number.

688631438 is a deficient number, since it is larger than the sum of its proper divisors (459483298).

688631438 is a wasteful number, since it uses less digits than its factorization.

688631438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590659.

The product of its digits is 663552, while the sum is 47.

The square root of 688631438 is about 26241.7880107282. The cubic root of 688631438 is about 883.0709845643.

The spelling of 688631438 in words is "six hundred eighty-eight million, six hundred thirty-one thousand, four hundred thirty-eight".