691956 has 48 divisors (see below), whose sum is σ = 1848000. Its totient is φ = 223776.

The previous prime is 691949. The next prime is 691973. The reversal of 691956 is 659196.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 691956.

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 691956.

It is an unprimeable number.

691956 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 15 ways as a sum of consecutive naturals, for example, 4570 + ... + 4718.

It is an arithmetic number, because the mean of its divisors is an integer number (38500).

2⁶⁹¹⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (924000).

691956 is an abundant number, since it is smaller than the sum of its proper divisors (1156044).

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

691956 is a wasteful number, since it uses less digits than its factorization.

691956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205 (or 197 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 691956 is about 831.8389267160. The cubic root of 691956 is about 88.4489794977.

It can be divided in two parts, 69 and 1956, that added together give a square (2025 = 45²).

The spelling of 691956 in words is "six hundred ninety-one thousand, nine hundred fifty-six".