688248779 has 2 divisors, whose sum is σ = 688248780. Its totient is φ = 688248778.

The previous prime is 688248767. The next prime is 688248809. The reversal of 688248779 is 977842886.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688248779 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (688248709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344124389 + 344124390.

It is an arithmetic number, because the mean of its divisors is an integer number (344124390).

Almost surely, 2^688248779 is an apocalyptic number.

688248779 is a deficient number, since it is larger than the sum of its proper divisors (1).

688248779 is an equidigital number, since it uses as much as digits as its factorization.

688248779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10838016, while the sum is 59.

The square root of 688248779 is about 26234.4959738128. The cubic root of 688248779 is about 882.9073858420.

The spelling of 688248779 in words is "six hundred eighty-eight million, two hundred forty-eight thousand, seven hundred seventy-nine".