531191 has 4 divisors (see below), whose sum is σ = 533352. Its totient is φ = 529032.

The previous prime is 531173. The next prime is 531197. The reversal of 531191 is 191135.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-531191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531197) 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, 656 + ... + 1221.

It is an arithmetic number, because the mean of its divisors is an integer number (133338).

2⁵³¹¹⁹¹ is an apocalyptic number.

531191 is a deficient number, since it is larger than the sum of its proper divisors (2161).

531191 is a wasteful number, since it uses less digits than its factorization.

531191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2160.

The product of its digits is 135, while the sum is 20.

The square root of 531191 is about 728.8285120658. The cubic root of 531191 is about 80.9872966920.

The spelling of 531191 in words is "five hundred thirty-one thousand, one hundred ninety-one".