6881681 has 4 divisors (see below), whose sum is σ = 6888000. Its totient is φ = 6875364.

The previous prime is 6881663. The next prime is 6881683. The reversal of 6881681 is 1861886.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6881681 is a prime.

It is a super-2 number, since 2×6881681² = 94715066771522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6881683) 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, 1061 + ... + 3858.

It is an arithmetic number, because the mean of its divisors is an integer number (1722000).

Almost surely, 2^6881681 is an apocalyptic number.

It is an amenable number.

6881681 is a deficient number, since it is larger than the sum of its proper divisors (6319).

6881681 is a wasteful number, since it uses less digits than its factorization.

6881681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6318.

The product of its digits is 18432, while the sum is 38.

The square root of 6881681 is about 2623.2958277709. The cubic root of 6881681 is about 190.2091970978.

The spelling of 6881681 in words is "six million, eight hundred eighty-one thousand, six hundred eighty-one".