11531009881 has 2 divisors, whose sum is σ = 11531009882. Its totient is φ = 11531009880.

The previous prime is 11531009851. The next prime is 11531009909. The reversal of 11531009881 is 18890013511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8712355600 + 2818654281 = 93340^2 + 53091^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11531009881 is a prime.

It is a super-2 number, since 2×11531009881² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11531009881.

It is not a weakly prime, because it can be changed into another prime (11531009851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5765504940 + 5765504941.

It is an arithmetic number, because the mean of its divisors is an integer number (5765504941).

Almost surely, 2^11531009881 is an apocalyptic number.

It is an amenable number.

11531009881 is a deficient number, since it is larger than the sum of its proper divisors (1).

11531009881 is an equidigital number, since it uses as much as digits as its factorization.

11531009881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 37.

The spelling of 11531009881 in words is "eleven billion, five hundred thirty-one million, nine thousand, eight hundred eighty-one".