691506845 has 16 divisors (see below), whose sum is σ = 880571520. Its totient is φ = 520179264.

The previous prime is 691506833. The next prime is 691506853. The reversal of 691506845 is 548605196.

It is a cyclic number.

It is not a de Polignac number, because 691506845 - 2²⁰ = 690458269 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 691506796 and 691506805.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44174 + ... + 57743.

It is an arithmetic number, because the mean of its divisors is an integer number (55035720).

Almost surely, 2^691506845 is an apocalyptic number.

It is an amenable number.

691506845 is a deficient number, since it is larger than the sum of its proper divisors (189064675).

691506845 is a wasteful number, since it uses less digits than its factorization.

691506845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102004.

The product of its (nonzero) digits is 259200, while the sum is 44.

The square root of 691506845 is about 26296.5177352440. The cubic root of 691506845 is about 884.2983767350.

The spelling of 691506845 in words is "six hundred ninety-one million, five hundred six thousand, eight hundred forty-five".