691599945 has 8 divisors (see below), whose sum is σ = 1106559936. Its totient is φ = 368853296.

The previous prime is 691599941. The next prime is 691599983. The reversal of 691599945 is 549995196.

691599945 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691599945 - 2² = 691599941 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691599941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23053317 + ... + 23053346.

It is an arithmetic number, because the mean of its divisors is an integer number (138319992).

Almost surely, 2^691599945 is an apocalyptic number.

It is an amenable number.

691599945 is a deficient number, since it is larger than the sum of its proper divisors (414959991).

691599945 is a wasteful number, since it uses less digits than its factorization.

691599945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46106671.

The product of its digits is 3936600, while the sum is 57.

The square root of 691599945 is about 26298.2878720270. The cubic root of 691599945 is about 884.3380603549.

The spelling of 691599945 in words is "six hundred ninety-one million, five hundred ninety-nine thousand, nine hundred forty-five".