6613681 has 4 divisors (see below), whose sum is σ = 6722164. Its totient is φ = 6505200.

The previous prime is 6613631. The next prime is 6613753. The reversal of 6613681 is 1863166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1703025 + 4910656 = 1305^2 + 2216^2 .

It is a cyclic number.

It is not a de Polignac number, because 6613681 - 2¹⁵ = 6580913 is a prime.

It is a super-2 number, since 2×6613681² = 87481552739522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6613601) 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, 54150 + ... + 54271.

It is an arithmetic number, because the mean of its divisors is an integer number (1680541).

Almost surely, 2^6613681 is an apocalyptic number.

6613681 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

6613681 is a deficient number, since it is larger than the sum of its proper divisors (108483).

6613681 is a wasteful number, since it uses less digits than its factorization.

6613681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108482.

The product of its digits is 5184, while the sum is 31.

The square root of 6613681 is about 2571.7077983317. The cubic root of 6613681 is about 187.7072647286.

The spelling of 6613681 in words is "six million, six hundred thirteen thousand, six hundred eighty-one".