689966917 has 4 divisors (see below), whose sum is σ = 697080076. Its totient is φ = 682853760.

The previous prime is 689966891. The next prime is 689966933. The reversal of 689966917 is 719669986.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 348419556 + 341547361 = 18666^2 + 18481^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689966917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689966957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3556434 + ... + 3556627.

It is an arithmetic number, because the mean of its divisors is an integer number (174270019).

Almost surely, 2^689966917 is an apocalyptic number.

It is an amenable number.

689966917 is a deficient number, since it is larger than the sum of its proper divisors (7113159).

689966917 is an equidigital number, since it uses as much as digits as its factorization.

689966917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7113158.

The product of its digits is 8817984, while the sum is 61.

The square root of 689966917 is about 26267.2213414362. The cubic root of 689966917 is about 883.6414693200.

The spelling of 689966917 in words is "six hundred eighty-nine million, nine hundred sixty-six thousand, nine hundred seventeen".