11813531 has 4 divisors (see below), whose sum is σ = 11863200. Its totient is φ = 11763864.

The previous prime is 11813509. The next prime is 11813537. The reversal of 11813531 is 13531811.

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-11813531 is a prime.

It is a super-3 number, since 3×11813531³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11813497 and 11813506.

It is not an unprimeable number, because it can be changed into a prime (11813537) 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, 24476 + ... + 24953.

It is an arithmetic number, because the mean of its divisors is an integer number (2965800).

Almost surely, 2^11813531 is an apocalyptic number.

11813531 is a deficient number, since it is larger than the sum of its proper divisors (49669).

11813531 is an equidigital number, since it uses as much as digits as its factorization.

11813531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49668.

The product of its digits is 360, while the sum is 23.

The square root of 11813531 is about 3437.0817563741. The cubic root of 11813531 is about 227.7507985672.

The spelling of 11813531 in words is "eleven million, eight hundred thirteen thousand, five hundred thirty-one".