811530531 has 24 divisors (see below), whose sum is σ = 1341010944. Its totient is φ = 463267440.

The previous prime is 811530491. The next prime is 811530563. The reversal of 811530531 is 135035118.

811530531 is a `hidden beast` number, since 81 + 1 + 53 + 0 + 531 = 666.

It is not a de Polignac number, because 811530531 - 2¹¹ = 811528483 is a prime.

It is a super-2 number, since 2×811530531² = 1317163605490283922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 811530495 and 811530504.

It is not an unprimeable number, because it can be changed into a prime (811530131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62830 + ... + 74636.

It is an arithmetic number, because the mean of its divisors is an integer number (55875456).

Almost surely, 2^811530531 is an apocalyptic number.

811530531 is a deficient number, since it is larger than the sum of its proper divisors (529480413).

811530531 is a wasteful number, since it uses less digits than its factorization.

811530531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12911 (or 12908 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 811530531 is about 28487.3749404890. The cubic root of 811530531 is about 932.7565077659.

Adding to 811530531 its reverse (135035118), we get a palindrome (946565649).

The spelling of 811530531 in words is "eight hundred eleven million, five hundred thirty thousand, five hundred thirty-one".