531660520521 has 48 divisors (see below), whose sum is σ = 871729622400. Its totient is φ = 309537801216.

The previous prime is 531660520519. The next prime is 531660520541. The reversal of 531660520521 is 125025066135.

531660520521 is a `hidden beast` number, since 5 + 3 + 1 + 6 + 605 + 20 + 5 + 21 = 666.

It is not a de Polignac number, because 531660520521 - 2¹ = 531660520519 is a prime.

It is a super-2 number, since 2×531660520521² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (531660520511) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1490745 + ... + 1812633.

It is an arithmetic number, because the mean of its divisors is an integer number (18161033800).

Almost surely, 2^531660520521 is an apocalyptic number.

It is an amenable number.

531660520521 is a deficient number, since it is larger than the sum of its proper divisors (340069101879).

531660520521 is a wasteful number, since it uses less digits than its factorization.

531660520521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322670 (or 322667 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

Adding to 531660520521 its reverse (125025066135), we get a palindrome (656685586656).

The spelling of 531660520521 in words is "five hundred thirty-one billion, six hundred sixty million, five hundred twenty thousand, five hundred twenty-one".