691368617 has 2 divisors, whose sum is σ = 691368618. Its totient is φ = 691368616.

The previous prime is 691368611. The next prime is 691368647. The reversal of 691368617 is 716863196.

It is a happy number.

691368617 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 520569856 + 170798761 = 22816^2 + 13069^2 .

It is a cyclic number.

It is not a de Polignac number, because 691368617 - 2²⁰ = 690320041 is a prime.

It is a super-3 number, since 3×691368617³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (691368611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345684308 + 345684309.

It is an arithmetic number, because the mean of its divisors is an integer number (345684309).

Almost surely, 2^691368617 is an apocalyptic number.

It is an amenable number.

691368617 is a deficient number, since it is larger than the sum of its proper divisors (1).

691368617 is an equidigital number, since it uses as much as digits as its factorization.

691368617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 47.

The square root of 691368617 is about 26293.8893471468. The cubic root of 691368617 is about 884.2394508581.

The spelling of 691368617 in words is "six hundred ninety-one million, three hundred sixty-eight thousand, six hundred seventeen".