691155 has 12 divisors (see below), whose sum is σ = 1198080. Its totient is φ = 368592.

The previous prime is 691153. The next prime is 691181. The reversal of 691155 is 551196.

It is not a de Polignac number, because 691155 - 2¹ = 691153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691151) 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 11 ways as a sum of consecutive naturals, for example, 7635 + ... + 7724.

It is an arithmetic number, because the mean of its divisors is an integer number (99840).

2⁶⁹¹¹⁵⁵ is an apocalyptic number.

691155 is a deficient number, since it is larger than the sum of its proper divisors (506925).

691155 is a wasteful number, since it uses less digits than its factorization.

691155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15370 (or 15367 counting only the distinct ones).

The product of its digits is 1350, while the sum is 27.

The square root of 691155 is about 831.3573238987. The cubic root of 691155 is about 88.4148371593.

The spelling of 691155 in words is "six hundred ninety-one thousand, one hundred fifty-five".