688535891 has 2 divisors, whose sum is σ = 688535892. Its totient is φ = 688535890.

The previous prime is 688535873. The next prime is 688535917. The reversal of 688535891 is 198535886.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 688535891 - 2²² = 684341587 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (688535191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344267945 + 344267946.

It is an arithmetic number, because the mean of its divisors is an integer number (344267946).

Almost surely, 2^688535891 is an apocalyptic number.

688535891 is a deficient number, since it is larger than the sum of its proper divisors (1).

688535891 is an equidigital number, since it uses as much as digits as its factorization.

688535891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2073600, while the sum is 53.

The square root of 688535891 is about 26239.9674351932. The cubic root of 688535891 is about 883.0301409038.

The spelling of 688535891 in words is "six hundred eighty-eight million, five hundred thirty-five thousand, eight hundred ninety-one".