688216307 has 2 divisors, whose sum is σ = 688216308. Its totient is φ = 688216306.

The previous prime is 688216301. The next prime is 688216339. The reversal of 688216307 is 703612886.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688216307 is a prime.

It is not a weakly prime, because it can be changed into another prime (688216301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344108153 + 344108154.

It is an arithmetic number, because the mean of its divisors is an integer number (344108154).

Almost surely, 2^688216307 is an apocalyptic number.

688216307 is a deficient number, since it is larger than the sum of its proper divisors (1).

688216307 is an equidigital number, since it uses as much as digits as its factorization.

688216307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 688216307 is about 26233.8770866984. The cubic root of 688216307 is about 882.8935002528.

The spelling of 688216307 in words is "six hundred eighty-eight million, two hundred sixteen thousand, three hundred seven".