691976693 has 2 divisors, whose sum is σ = 691976694. Its totient is φ = 691976692.

The previous prime is 691976647. The next prime is 691976707. The reversal of 691976693 is 396679196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 537173329 + 154803364 = 23177^2 + 12442^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691976693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691976293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345988346 + 345988347.

It is an arithmetic number, because the mean of its divisors is an integer number (345988347).

Almost surely, 2^691976693 is an apocalyptic number.

It is an amenable number.

691976693 is a deficient number, since it is larger than the sum of its proper divisors (1).

691976693 is an equidigital number, since it uses as much as digits as its factorization.

691976693 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3306744, while the sum is 56.

The square root of 691976693 is about 26305.4498726024. The cubic root of 691976693 is about 884.4986118017.

The spelling of 691976693 in words is "six hundred ninety-one million, nine hundred seventy-six thousand, six hundred ninety-three".