691405108 has 6 divisors (see below), whose sum is σ = 1209958946. Its totient is φ = 345702552.

The previous prime is 691405103. The next prime is 691405123. The reversal of 691405108 is 801504196.

It can be written as a sum of positive squares in only one way, i.e., 674856484 + 16548624 = 25978^2 + 4068^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691405103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86425635 + ... + 86425642.

Almost surely, 2^691405108 is an apocalyptic number.

It is an amenable number.

691405108 is a deficient number, since it is larger than the sum of its proper divisors (518553838).

691405108 is a wasteful number, since it uses less digits than its factorization.

691405108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172851281 (or 172851279 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 691405108 is about 26294.5832444631. The cubic root of 691405108 is about 884.2550075444.

The spelling of 691405108 in words is "six hundred ninety-one million, four hundred five thousand, one hundred eight".