656191 has 4 divisors (see below), whose sum is σ = 662112. Its totient is φ = 650272.

The previous prime is 656171. The next prime is 656221. The reversal of 656191 is 191656.

656191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 656191 - 2⁷ = 656063 is a prime.

It is a Duffinian number.

656191 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2791 + ... + 3016.

It is an arithmetic number, because the mean of its divisors is an integer number (165528).

2⁶⁵⁶¹⁹¹ is an apocalyptic number.

656191 is a deficient number, since it is larger than the sum of its proper divisors (5921).

656191 is a wasteful number, since it uses less digits than its factorization.

656191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5920.

The product of its digits is 1620, while the sum is 28.

The square root of 656191 is about 810.0561708919. The cubic root of 656191 is about 86.8980617829.

The spelling of 656191 in words is "six hundred fifty-six thousand, one hundred ninety-one".