6981696665 has 4 divisors (see below), whose sum is σ = 8378036004. Its totient is φ = 5585357328.

The previous prime is 6981696647. The next prime is 6981696679. The reversal of 6981696665 is 5666961896.

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 4720789264 + 2260907401 = 68708^2 + 47549^2 .

It is a cyclic number.

It is not a de Polignac number, because 6981696665 - 2¹⁰ = 6981695641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6981696598 and 6981696607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 698169662 + ... + 698169671.

It is an arithmetic number, because the mean of its divisors is an integer number (2094509001).

Almost surely, 2^6981696665 is an apocalyptic number.

It is an amenable number.

6981696665 is a deficient number, since it is larger than the sum of its proper divisors (1396339339).

6981696665 is a wasteful number, since it uses less digits than its factorization.

6981696665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1396339338.

The product of its digits is 25194240, while the sum is 62.

The square root of 6981696665 is about 83556.5477087224. The cubic root of 6981696665 is about 1911.2624407922.

The spelling of 6981696665 in words is "six billion, nine hundred eighty-one million, six hundred ninety-six thousand, six hundred sixty-five".