531121646813 has 4 divisors (see below), whose sum is σ = 531330834720. Its totient is φ = 530912458908.

The previous prime is 531121646807. The next prime is 531121646827. The reversal of 531121646813 is 318646121135.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 531121646813 - 2²⁰ = 531120598237 is a prime.

It is a super-2 number, since 2×531121646813² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (531121646843) 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, 104590145 + ... + 104595222.

It is an arithmetic number, because the mean of its divisors is an integer number (132832708680).

Almost surely, 2^531121646813 is an apocalyptic number.

It is an amenable number.

531121646813 is a deficient number, since it is larger than the sum of its proper divisors (209187907).

531121646813 is a wasteful number, since it uses less digits than its factorization.

531121646813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209187906.

The product of its digits is 103680, while the sum is 41.

Adding to 531121646813 its reverse (318646121135), we get a palindrome (849767767948).

The spelling of 531121646813 in words is "five hundred thirty-one billion, one hundred twenty-one million, six hundred forty-six thousand, eight hundred thirteen".