688400268 has 12 divisors (see below), whose sum is σ = 1606267320. Its totient is φ = 229466752.

The previous prime is 688400249. The next prime is 688400269. The reversal of 688400268 is 862004886.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (688400269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28683333 + ... + 28683356.

It is an arithmetic number, because the mean of its divisors is an integer number (133855610).

Almost surely, 2^688400268 is an apocalyptic number.

It is an amenable number.

688400268 is an abundant number, since it is smaller than the sum of its proper divisors (917867052).

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

688400268 is a wasteful number, since it uses less digits than its factorization.

688400268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57366696 (or 57366694 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 42.

The square root of 688400268 is about 26237.3830249894. The cubic root of 688400268 is about 882.9721593895.

The spelling of 688400268 in words is "six hundred eighty-eight million, four hundred thousand, two hundred sixty-eight".