688342841 has 2 divisors, whose sum is σ = 688342842. Its totient is φ = 688342840.

The previous prime is 688342829. The next prime is 688342843. The reversal of 688342841 is 148243886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 661261225 + 27081616 = 25715^2 + 5204^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688342841 is a prime.

Together with 688342843, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 688342792 and 688342801.

It is not a weakly prime, because it can be changed into another prime (688342843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344171420 + 344171421.

It is an arithmetic number, because the mean of its divisors is an integer number (344171421).

Almost surely, 2^688342841 is an apocalyptic number.

It is an amenable number.

688342841 is a deficient number, since it is larger than the sum of its proper divisors (1).

688342841 is an equidigital number, since it uses as much as digits as its factorization.

688342841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 294912, while the sum is 44.

The square root of 688342841 is about 26236.2886285389. The cubic root of 688342841 is about 882.9476059165.

The spelling of 688342841 in words is "six hundred eighty-eight million, three hundred forty-two thousand, eight hundred forty-one".