688357442 has 8 divisors (see below), whose sum is σ = 1046680716. Its totient is φ = 339463872.

The previous prime is 688357391. The next prime is 688357451. The reversal of 688357442 is 244753886.

It can be written as a sum of positive squares in 2 ways, for example, as 656333161 + 32024281 = 25619^2 + 5659^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 2357243 + ... + 2357534.

Almost surely, 2^688357442 is an apocalyptic number.

688357442 is a deficient number, since it is larger than the sum of its proper divisors (358323274).

688357442 is a wasteful number, since it uses less digits than its factorization.

688357442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4714852.

The product of its digits is 1290240, while the sum is 47.

The square root of 688357442 is about 26236.5668866946. The cubic root of 688357442 is about 882.9538488457.

The spelling of 688357442 in words is "six hundred eighty-eight million, three hundred fifty-seven thousand, four hundred forty-two".