6686981 has 12 divisors (see below), whose sum is σ = 7824960. Its totient is φ = 5697720.

The previous prime is 6686947. The next prime is 6686983. The reversal of 6686981 is 1896866.

It is not a de Polignac number, because 6686981 - 2¹⁸ = 6424837 is a prime.

It is a super-2 number, since 2×6686981² = 89431429788722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6686983) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11426 + ... + 11996.

It is an arithmetic number, because the mean of its divisors is an integer number (652080).

Almost surely, 2^6686981 is an apocalyptic number.

It is an amenable number.

6686981 is a deficient number, since it is larger than the sum of its proper divisors (1137979).

6686981 is a wasteful number, since it uses less digits than its factorization.

6686981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 824 (or 817 counting only the distinct ones).

The product of its digits is 124416, while the sum is 44.

The square root of 6686981 is about 2585.9197590026. The cubic root of 6686981 is about 188.3981771303.

It can be divided in two parts, 6686 and 981, that added together give a palindrome (7667).

The spelling of 6686981 in words is "six million, six hundred eighty-six thousand, nine hundred eighty-one".