691047 has 18 divisors (see below), whose sum is σ = 1161888. Its totient is φ = 394632.

The previous prime is 691037. The next prime is 691051. The reversal of 691047 is 740196.

It is not a de Polignac number, because 691047 - 2⁷ = 690919 is a prime.

691047 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 691047.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 691047.

It is not an unprimeable number, because it can be changed into a prime (691037) 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 in 17 ways as a sum of consecutive naturals, for example, 343 + ... + 1224.

2⁶⁹¹⁰⁴⁷ is an apocalyptic number.

691047 is a deficient number, since it is larger than the sum of its proper divisors (470841).

691047 is a wasteful number, since it uses less digits than its factorization.

691047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1587 (or 1577 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 691047 is about 831.2923673414. The cubic root of 691047 is about 88.4102316802.

The spelling of 691047 in words is "six hundred ninety-one thousand, forty-seven".