6881581 has 4 divisors (see below), whose sum is σ = 7864672. Its totient is φ = 5898492.

The previous prime is 6881579. The next prime is 6881603. The reversal of 6881581 is 1851886.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1851886 = 2 ⋅925943.

It is a cyclic number.

It is not a de Polignac number, because 6881581 - 2¹ = 6881579 is a prime.

It is a super-2 number, since 2×6881581² = 94712314119122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6881581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6881551) 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, 491535 + ... + 491548.

It is an arithmetic number, because the mean of its divisors is an integer number (1966168).

Almost surely, 2^6881581 is an apocalyptic number.

It is an amenable number.

6881581 is a deficient number, since it is larger than the sum of its proper divisors (983091).

6881581 is an equidigital number, since it uses as much as digits as its factorization.

6881581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 983090.

The product of its digits is 15360, while the sum is 37.

The square root of 6881581 is about 2623.2767677087. The cubic root of 6881581 is about 190.2082757623.

The spelling of 6881581 in words is "six million, eight hundred eighty-one thousand, five hundred eighty-one".