688901 has 4 divisors (see below), whose sum is σ = 698412. Its totient is φ = 679392.

The previous prime is 688889. The next prime is 688907. The reversal of 688901 is 109886.

It is a Cunningham number, because it is equal to 830²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 391876 + 297025 = 626^2 + 545^2 .

It is a cyclic number.

It is not a de Polignac number, because 688901 - 2¹⁸ = 426757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688907) 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 in 3 ways as a sum of consecutive naturals, for example, 4646 + ... + 4791.

It is an arithmetic number, because the mean of its divisors is an integer number (174603).

2⁶⁸⁸⁹⁰¹ is an apocalyptic number.

It is an amenable number.

688901 is a deficient number, since it is larger than the sum of its proper divisors (9511).

688901 is an equidigital number, since it uses as much as digits as its factorization.

688901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9510.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 688901 is about 830.0006024094. Note that the first 3 decimals coincide. The cubic root of 688901 is about 88.3186194392.

The spelling of 688901 in words is "six hundred eighty-eight thousand, nine hundred one".