688005091 has 2 divisors, whose sum is σ = 688005092. Its totient is φ = 688005090.

The previous prime is 688005089. The next prime is 688005139. The reversal of 688005091 is 190500886.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 688005091 - 2¹ = 688005089 is a prime.

Together with 688005089, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688005091.

It is not a weakly prime, because it can be changed into another prime (688005001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344002545 + 344002546.

It is an arithmetic number, because the mean of its divisors is an integer number (344002546).

Almost surely, 2^688005091 is an apocalyptic number.

688005091 is a deficient number, since it is larger than the sum of its proper divisors (1).

688005091 is an equidigital number, since it uses as much as digits as its factorization.

688005091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 37.

The square root of 688005091 is about 26229.8511433062. The cubic root of 688005091 is about 882.8031699733.

The spelling of 688005091 in words is "six hundred eighty-eight million, five thousand, ninety-one".