688903987 has 2 divisors, whose sum is σ = 688903988. Its totient is φ = 688903986.

The previous prime is 688903973. The next prime is 688903997. The reversal of 688903987 is 789309886.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 688903987 - 2²⁷ = 554686259 is a prime.

It is not a weakly prime, because it can be changed into another prime (688903907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344451993 + 344451994.

It is an arithmetic number, because the mean of its divisors is an integer number (344451994).

Almost surely, 2^688903987 is an apocalyptic number.

688903987 is a deficient number, since it is larger than the sum of its proper divisors (1).

688903987 is an equidigital number, since it uses as much as digits as its factorization.

688903987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5225472, while the sum is 58.

The square root of 688903987 is about 26246.9805311011. The cubic root of 688903987 is about 883.1874708563.

The spelling of 688903987 in words is "six hundred eighty-eight million, nine hundred three thousand, nine hundred eighty-seven".