688841 has 8 divisors (see below), whose sum is σ = 721224. Its totient is φ = 657280.

The previous prime is 688813. The next prime is 688861. The reversal of 688841 is 148886.

688841 = T₁₃₄ + T₁₃₅ + ... + T₁₈₆.

It can be written as a sum of positive squares in 4 ways, for example, as 1600 + 687241 = 40^2 + 829^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 688841 - 2⁶ = 688777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (688861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2015 + ... + 2331.

It is an arithmetic number, because the mean of its divisors is an integer number (90153).

2⁶⁸⁸⁸⁴¹ is an apocalyptic number.

It is an amenable number.

688841 is a deficient number, since it is larger than the sum of its proper divisors (32383).

688841 is a wasteful number, since it uses less digits than its factorization.

688841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411.

The product of its digits is 12288, while the sum is 35.

The square root of 688841 is about 829.9644570703. The cubic root of 688841 is about 88.3160553208.

The spelling of 688841 in words is "six hundred eighty-eight thousand, eight hundred forty-one".