688354 has 4 divisors (see below), whose sum is σ = 1032534. Its totient is φ = 344176.

The previous prime is 688339. The next prime is 688357. The reversal of 688354 is 453886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 453886 = 2 ⋅226943.

It can be written as a sum of positive squares in only one way, i.e., 677329 + 11025 = 823^2 + 105^2 .

It is not an unprimeable number, because it can be changed into a prime (688357) by changing a digit.

688354 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172087 + ... + 172090.

2⁶⁸⁸³⁵⁴ is an apocalyptic number.

688354 is a deficient number, since it is larger than the sum of its proper divisors (344180).

688354 is a wasteful number, since it uses less digits than its factorization.

688354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344179.

The product of its digits is 23040, while the sum is 34.

The square root of 688354 is about 829.6710191395. The cubic root of 688354 is about 88.2952377162.

The spelling of 688354 in words is "six hundred eighty-eight thousand, three hundred fifty-four".