691880 has 48 divisors (see below), whose sum is σ = 1816020. Its totient is φ = 236544.

The previous prime is 691877. The next prime is 691891. The reversal of 691880 is 88196.

It can be written as a sum of positive squares in 2 ways, for example, as 682276 + 9604 = 826^2 + 98^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1784 + ... + 2136.

2⁶⁹¹⁸⁸⁰ 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 691880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (908010).

691880 is an abundant number, since it is smaller than the sum of its proper divisors (1124140).

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

691880 is a wasteful number, since it uses less digits than its factorization.

691880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 691880 is about 831.7932435407. The cubic root of 691880 is about 88.4457411566.

The spelling of 691880 in words is "six hundred ninety-one thousand, eight hundred eighty".