691867 has 4 divisors (see below), whose sum is σ = 754776. Its totient is φ = 628960.

The previous prime is 691843. The next prime is 691871. The reversal of 691867 is 768196.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 691867 - 2⁷ = 691739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691837) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 31438 + ... + 31459.

It is an arithmetic number, because the mean of its divisors is an integer number (188694).

2⁶⁹¹⁸⁶⁷ is an apocalyptic number.

691867 is a deficient number, since it is larger than the sum of its proper divisors (62909).

691867 is a wasteful number, since it uses less digits than its factorization.

691867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62908.

The product of its digits is 18144, while the sum is 37.

The square root of 691867 is about 831.7854290621. The cubic root of 691867 is about 88.4451872061.

It can be divided in two parts, 69 and 1867, that added together give a square (1936 = 44²).

The spelling of 691867 in words is "six hundred ninety-one thousand, eight hundred sixty-seven".