6909681 has 4 divisors (see below), whose sum is σ = 9212912. Its totient is φ = 4606452.

The previous prime is 6909677. The next prime is 6909709. The reversal of 6909681 is 1869096.

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 not a de Polignac number, because 6909681 - 2² = 6909677 is a prime.

It is a super-3 number, since 3×6909681³ (a number of 21 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6909641) 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, 1151611 + ... + 1151616.

It is an arithmetic number, because the mean of its divisors is an integer number (2303228).

Almost surely, 2^6909681 is an apocalyptic number.

It is an amenable number.

6909681 is a deficient number, since it is larger than the sum of its proper divisors (2303231).

6909681 is a wasteful number, since it uses less digits than its factorization.

6909681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2303230.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 6909681 is about 2628.6272082591. The cubic root of 6909681 is about 190.4668207107.

The spelling of 6909681 in words is "six million, nine hundred nine thousand, six hundred eighty-one".