691693 has 2 divisors, whose sum is σ = 691694. Its totient is φ = 691692.

The previous prime is 691687. The next prime is 691697. The reversal of 691693 is 396196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 499849 + 191844 = 707^2 + 438^2 .

It is a cyclic number.

It is not a de Polignac number, because 691693 - 2⁵ = 691661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345846 + 345847.

It is an arithmetic number, because the mean of its divisors is an integer number (345847).

2⁶⁹¹⁶⁹³ is an apocalyptic number.

It is an amenable number.

691693 is a deficient number, since it is larger than the sum of its proper divisors (1).

691693 is an equidigital number, since it uses as much as digits as its factorization.

691693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8748, while the sum is 34.

The square root of 691693 is about 831.6808282027. The cubic root of 691693 is about 88.4377721235.

The spelling of 691693 in words is "six hundred ninety-one thousand, six hundred ninety-three".