688352778 has 24 divisors (see below), whose sum is σ = 1493200800. Its totient is φ = 229178664.

The previous prime is 688352771. The next prime is 688352839. The reversal of 688352778 is 877253886.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (688352771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6798 + ... + 37721.

It is an arithmetic number, because the mean of its divisors is an integer number (62216700).

Almost surely, 2^688352778 is an apocalyptic number.

688352778 is an abundant number, since it is smaller than the sum of its proper divisors (804848022).

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

688352778 is a wasteful number, since it uses less digits than its factorization.

688352778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45386 (or 45383 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The square root of 688352778 is about 26236.4780029637. The cubic root of 688352778 is about 882.9518546753.

The spelling of 688352778 in words is "six hundred eighty-eight million, three hundred fifty-two thousand, seven hundred seventy-eight".