6660581 has 4 divisors (see below), whose sum is σ = 6754464. Its totient is φ = 6566700.

The previous prime is 6660557. The next prime is 6660587. The reversal of 6660581 is 1850666.

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 6660581 - 2¹⁸ = 6398437 is a prime.

It is a super-2 number, since 2×6660581² = 88726678515122, 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 (6660587) 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, 46835 + ... + 46976.

It is an arithmetic number, because the mean of its divisors is an integer number (1688616).

Almost surely, 2^6660581 is an apocalyptic number.

It is an amenable number.

6660581 is a deficient number, since it is larger than the sum of its proper divisors (93883).

6660581 is an equidigital number, since it uses as much as digits as its factorization.

6660581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93882.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 6660581 is about 2580.8101441214. The cubic root of 6660581 is about 188.1499200256.

The spelling of 6660581 in words is "six million, six hundred sixty thousand, five hundred eighty-one".