11681784857 has 4 divisors (see below), whose sum is σ = 11682128256. Its totient is φ = 11681441460.

The previous prime is 11681784853. The next prime is 11681784859. The reversal of 11681784857 is 75848718611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75848718611 = 138637 ⋅547103.

It is a cyclic number.

It is not a de Polignac number, because 11681784857 - 2² = 11681784853 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11681784853) 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, 114269 + ... + 190842.

It is an arithmetic number, because the mean of its divisors is an integer number (2920532064).

Almost surely, 2^11681784857 is an apocalyptic number.

It is an amenable number.

11681784857 is a deficient number, since it is larger than the sum of its proper divisors (343399).

11681784857 is an equidigital number, since it uses as much as digits as its factorization.

11681784857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343398.

The product of its digits is 3010560, while the sum is 56.

The spelling of 11681784857 in words is "eleven billion, six hundred eighty-one million, seven hundred eighty-four thousand, eight hundred fifty-seven".