688654 has 4 divisors (see below), whose sum is σ = 1032984. Its totient is φ = 344326.

The previous prime is 688637. The next prime is 688657. The reversal of 688654 is 456886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 456886 = 2 ⋅228443.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688657) by changing a digit.

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, 172162 + ... + 172165.

It is an arithmetic number, because the mean of its divisors is an integer number (258246).

2⁶⁸⁸⁶⁵⁴ is an apocalyptic number.

688654 is a deficient number, since it is larger than the sum of its proper divisors (344330).

688654 is a wasteful number, since it uses less digits than its factorization.

688654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344329.

The product of its digits is 46080, while the sum is 37.

The square root of 688654 is about 829.8517939970. The cubic root of 688654 is about 88.3080628635.

The spelling of 688654 in words is "six hundred eighty-eight thousand, six hundred fifty-four".