691966 has 16 divisors (see below), whose sum is σ = 1150848. Its totient is φ = 309400.

The previous prime is 691949. The next prime is 691973. The reversal of 691966 is 669196.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1341 + ... + 1783.

It is an arithmetic number, because the mean of its divisors is an integer number (71928).

2⁶⁹¹⁹⁶⁶ is an apocalyptic number.

691966 is a deficient number, since it is larger than the sum of its proper divisors (458882).

691966 is a wasteful number, since it uses less digits than its factorization.

691966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527.

The product of its digits is 17496, while the sum is 37.

The square root of 691966 is about 831.8449374733. The cubic root of 691966 is about 88.4494055775.

It can be divided in two parts, 6919 and 66, that multiplied together give a palindrome (456654).

The spelling of 691966 in words is "six hundred ninety-one thousand, nine hundred sixty-six".