691393109 has 16 divisors (see below), whose sum is σ = 808937280. Its totient is φ = 584213760.

The previous prime is 691393103. The next prime is 691393121. The reversal of 691393109 is 901393196.

691393109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 691393109 - 2⁸ = 691392853 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 (691393103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20132 + ... + 42285.

It is an arithmetic number, because the mean of its divisors is an integer number (50558580).

Almost surely, 2^691393109 is an apocalyptic number.

It is an amenable number.

691393109 is a deficient number, since it is larger than the sum of its proper divisors (117544171).

691393109 is a wasteful number, since it uses less digits than its factorization.

691393109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62500.

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 691393109 is about 26294.3550786096. The cubic root of 691393109 is about 884.2498922427.

The spelling of 691393109 in words is "six hundred ninety-one million, three hundred ninety-three thousand, one hundred nine".