11813315281 has 4 divisors (see below), whose sum is σ = 12101444964. Its totient is φ = 11525185600.

The previous prime is 11813315257. The next prime is 11813315287. The reversal of 11813315281 is 18251331811.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1083463056 + 10729852225 = 32916^2 + 103585^2 .

It is a cyclic number.

It is not a de Polignac number, because 11813315281 - 2⁹ = 11813314769 is a prime.

It is a super-2 number, since 2×11813315281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11813315287) 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, 144064780 + ... + 144064861.

It is an arithmetic number, because the mean of its divisors is an integer number (3025361241).

Almost surely, 2^11813315281 is an apocalyptic number.

It is an amenable number.

11813315281 is a deficient number, since it is larger than the sum of its proper divisors (288129683).

11813315281 is an equidigital number, since it uses as much as digits as its factorization.

11813315281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288129682.

The product of its digits is 5760, while the sum is 34.

The spelling of 11813315281 in words is "eleven billion, eight hundred thirteen million, three hundred fifteen thousand, two hundred eighty-one".