6683887781 has 8 divisors (see below), whose sum is σ = 6919042680. Its totient is φ = 6449044672.

The previous prime is 6683887757. The next prime is 6683887783. The reversal of 6683887781 is 1877883866.

It can be written as a sum of positive squares in 4 ways, for example, as 1360872100 + 5323015681 = 36890^2 + 72959^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6683887781 - 2¹⁰ = 6683886757 is a prime.

It is a super-2 number, since 2×6683887781² = 89348711738002207922, which 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 (6683887783) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 33890 + ... + 120483.

It is an arithmetic number, because the mean of its divisors is an integer number (864880335).

Almost surely, 2^6683887781 is an apocalyptic number.

It is an amenable number.

6683887781 is a deficient number, since it is larger than the sum of its proper divisors (235154899).

6683887781 is a wasteful number, since it uses less digits than its factorization.

6683887781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155895.

The product of its digits is 21676032, while the sum is 62.

The square root of 6683887781 is about 81755.0474343939. The cubic root of 6683887781 is about 1883.6912332655.

The spelling of 6683887781 in words is "six billion, six hundred eighty-three million, eight hundred eighty-seven thousand, seven hundred eighty-one".