688691149 has 2 divisors, whose sum is σ = 688691150. Its totient is φ = 688691148.

The previous prime is 688691147. The next prime is 688691177. The reversal of 688691149 is 941196886.

688691149 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 647346249 + 41344900 = 25443^2 + 6430^2 .

It is a cyclic number.

It is not a de Polignac number, because 688691149 - 2¹ = 688691147 is a prime.

Together with 688691147, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 688691096 and 688691105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688691147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344345574 + 344345575.

It is an arithmetic number, because the mean of its divisors is an integer number (344345575).

Almost surely, 2^688691149 is an apocalyptic number.

It is an amenable number.

688691149 is a deficient number, since it is larger than the sum of its proper divisors (1).

688691149 is an equidigital number, since it uses as much as digits as its factorization.

688691149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 52.

The square root of 688691149 is about 26242.9256943657. The cubic root of 688691149 is about 883.0965074225.

The spelling of 688691149 in words is "six hundred eighty-eight million, six hundred ninety-one thousand, one hundred forty-nine".