6601681 has 4 divisors (see below), whose sum is σ = 6612592. Its totient is φ = 6590772.

The previous prime is 6601649. The next prime is 6601691. The reversal of 6601681 is 1861066.

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 a cyclic number.

It is not a de Polignac number, because 6601681 - 2⁵ = 6601649 is a prime.

It is a super-2 number, since 2×6601681² = 87164384051522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6601601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4491 + ... + 5776.

It is an arithmetic number, because the mean of its divisors is an integer number (1653148).

Almost surely, 2^6601681 is an apocalyptic number.

It is an amenable number.

6601681 is a deficient number, since it is larger than the sum of its proper divisors (10911).

6601681 is a wasteful number, since it uses less digits than its factorization.

6601681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10910.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 6601681 is about 2569.3736590850. The cubic root of 6601681 is about 187.5936693460.

The spelling of 6601681 in words is "six million, six hundred one thousand, six hundred eighty-one".