691968 has 72 divisors (see below), whose sum is σ = 1986768. Its totient is φ = 212992.

The previous prime is 691949. The next prime is 691973. The reversal of 691968 is 869196.

It is a congruent number.

It is an unprimeable number.

691968 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 (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13030 + ... + 13082.

It is an arithmetic number, because the mean of its divisors is an integer number (27594).

2⁶⁹¹⁹⁶⁸ is an apocalyptic number.

691968 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993384).

691968 is an abundant number, since it is smaller than the sum of its proper divisors (1294800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691968 is a wasteful number, since it uses less digits than its factorization.

691968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 75 counting only the distinct ones).

The product of its digits is 23328, while the sum is 39.

The square root of 691968 is about 831.8461396196. The cubic root of 691968 is about 88.4494907930.

The spelling of 691968 in words is "six hundred ninety-one thousand, nine hundred sixty-eight".