2118671681 has 4 divisors (see below), whose sum is σ = 2421339072. Its totient is φ = 1816004292.

The previous prime is 2118671671. The next prime is 2118671693. The reversal of 2118671681 is 1861768112.

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.

It is a cyclic number.

It is not a de Polignac number, because 2118671681 - 2⁶ = 2118671617 is a prime.

It is a super-2 number, since 2×2118671681² = 8977539383742731522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2118671641) 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, 151333685 + ... + 151333698.

It is an arithmetic number, because the mean of its divisors is an integer number (605334768).

Almost surely, 2^2118671681 is an apocalyptic number.

It is an amenable number.

2118671681 is a deficient number, since it is larger than the sum of its proper divisors (302667391).

2118671681 is an equidigital number, since it uses as much as digits as its factorization.

2118671681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302667390.

The product of its digits is 32256, while the sum is 41.

The square root of 2118671681 is about 46029.0308501059. The cubic root of 2118671681 is about 1284.3632996694.

The spelling of 2118671681 in words is "two billion, one hundred eighteen million, six hundred seventy-one thousand, six hundred eighty-one".