531195721 has 12 divisors (see below), whose sum is σ = 618560580. Its totient is φ = 454839840.

The previous prime is 531195689. The next prime is 531195773. The reversal of 531195721 is 127591135.

It can be written as a sum of positive squares in 2 ways, for example, as 167340096 + 363855625 = 12936^2 + 19075^2 .

It is not a de Polignac number, because 531195721 - 2⁵ = 531195689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (531192721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47311 + ... + 57451.

It is an arithmetic number, because the mean of its divisors is an integer number (51546715).

Almost surely, 2^531195721 is an apocalyptic number.

It is an amenable number.

531195721 is a deficient number, since it is larger than the sum of its proper divisors (87364859).

531195721 is a wasteful number, since it uses less digits than its factorization.

531195721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11224 (or 11217 counting only the distinct ones).

The product of its digits is 9450, while the sum is 34.

The square root of 531195721 is about 23047.6836363223. The cubic root of 531195721 is about 809.8753661816.

The spelling of 531195721 in words is "five hundred thirty-one million, one hundred ninety-five thousand, seven hundred twenty-one".