691886 has 24 divisors (see below), whose sum is σ = 1185840. Its totient is φ = 302016.

The previous prime is 691877. The next prime is 691891. The reversal of 691886 is 688196.

691886 is nontrivially palindromic in base 12.

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 691886.

It is an unprimeable number.

691886 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 11 ways as a sum of consecutive naturals, for example, 7730 + ... + 7818.

It is an arithmetic number, because the mean of its divisors is an integer number (49410).

2⁶⁹¹⁸⁸⁶ is an apocalyptic number.

691886 is a deficient number, since it is larger than the sum of its proper divisors (493954).

691886 is a wasteful number, since it uses less digits than its factorization.

691886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140 (or 127 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

The square root of 691886 is about 831.7968501984. The cubic root of 691886 is about 88.4459968237.

The spelling of 691886 in words is "six hundred ninety-one thousand, eight hundred eighty-six".