7681681 has 24 divisors (see below), whose sum is σ = 9703680. Its totient is φ = 6041952.

The previous prime is 7681657. The next prime is 7681691. The reversal of 7681681 is 1861867.

It is not a de Polignac number, because 7681681 - 2⁹ = 7681169 is a prime.

It is a super-2 number, since 2×7681681² = 118016445971522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 7681681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7681631) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34336 + ... + 34558.

It is an arithmetic number, because the mean of its divisors is an integer number (404320).

Almost surely, 2^7681681 is an apocalyptic number.

It is an amenable number.

7681681 is a deficient number, since it is larger than the sum of its proper divisors (2021999).

7681681 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (7681680) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (293).

7681681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293 (or 286 counting only the distinct ones).

The product of its digits is 16128, while the sum is 37.

The square root of 7681681 is about 2771.5845648293. The cubic root of 7681681 is about 197.3113596967.

The spelling of 7681681 in words is "seven million, six hundred eighty-one thousand, six hundred eighty-one".