6606781 has 4 divisors (see below), whose sum is σ = 6767964. Its totient is φ = 6445600.

The previous prime is 6606779. The next prime is 6606811. The reversal of 6606781 is 1876066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1876066 = 2 ⋅938033.

It can be written as a sum of positive squares in 2 ways, for example, as 525625 + 6081156 = 725^2 + 2466^2 .

It is a cyclic number.

It is not a de Polignac number, because 6606781 - 2¹ = 6606779 is a prime.

It is a super-2 number, since 2×6606781² = 87299110363922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6606731) 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, 80530 + ... + 80611.

It is an arithmetic number, because the mean of its divisors is an integer number (1691991).

Almost surely, 2^6606781 is an apocalyptic number.

It is an amenable number.

6606781 is a deficient number, since it is larger than the sum of its proper divisors (161183).

6606781 is a wasteful number, since it uses less digits than its factorization.

6606781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161182.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 6606781 is about 2570.3659272563. The cubic root of 6606781 is about 187.6419641895.

The spelling of 6606781 in words is "six million, six hundred six thousand, seven hundred eighty-one".