11851840447 has 4 divisors (see below), whose sum is σ = 12028733656. Its totient is φ = 11674947240.

The previous prime is 11851840433. The next prime is 11851840457. The reversal of 11851840447 is 74404815811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74404815811 = 1567 ⋅47482333.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11851840447 is a prime.

It is a super-2 number, since 2×11851840447² (a number of 21 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 (11851840417) 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, 88446504 + ... + 88446637.

It is an arithmetic number, because the mean of its divisors is an integer number (3007183414).

Almost surely, 2^11851840447 is an apocalyptic number.

11851840447 is a deficient number, since it is larger than the sum of its proper divisors (176893209).

11851840447 is an equidigital number, since it uses as much as digits as its factorization.

11851840447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176893208.

The product of its (nonzero) digits is 143360, while the sum is 43.

The spelling of 11851840447 in words is "eleven billion, eight hundred fifty-one million, eight hundred forty thousand, four hundred forty-seven".