688972693 has 2 divisors, whose sum is σ = 688972694. Its totient is φ = 688972692.

The previous prime is 688972663. The next prime is 688972721. The reversal of 688972693 is 396279886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 671483569 + 17489124 = 25913^2 + 4182^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688972693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688972663) 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, 344486346 + 344486347.

It is an arithmetic number, because the mean of its divisors is an integer number (344486347).

Almost surely, 2^688972693 is an apocalyptic number.

It is an amenable number.

688972693 is a deficient number, since it is larger than the sum of its proper divisors (1).

688972693 is an equidigital number, since it uses as much as digits as its factorization.

688972693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 58.

The square root of 688972693 is about 26248.2893347357. The cubic root of 688972693 is about 883.2168306618.

The spelling of 688972693 in words is "six hundred eighty-eight million, nine hundred seventy-two thousand, six hundred ninety-three".