7891813841 has 4 divisors (see below), whose sum is σ = 7897789284. Its totient is φ = 7885838400.

The previous prime is 7891813793. The next prime is 7891813859. The reversal of 7891813841 is 1483181987.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1483181987 = 7 ⋅211883141.

It can be written as a sum of positive squares in 2 ways, for example, as 7123360000 + 768453841 = 84400^2 + 27721^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7891813841 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7891813841.

It is not an unprimeable number, because it can be changed into a prime (7891813861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2985740 + ... + 2988381.

It is an arithmetic number, because the mean of its divisors is an integer number (1974447321).

Almost surely, 2^7891813841 is an apocalyptic number.

It is an amenable number.

7891813841 is a deficient number, since it is larger than the sum of its proper divisors (5975443).

7891813841 is a wasteful number, since it uses less digits than its factorization.

7891813841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5975442.

The product of its digits is 387072, while the sum is 50.

The square root of 7891813841 is about 88835.8814950356. The cubic root of 7891813841 is about 1990.9435389068.

The spelling of 7891813841 in words is "seven billion, eight hundred ninety-one million, eight hundred thirteen thousand, eight hundred forty-one".