6581945 has 4 divisors (see below), whose sum is σ = 7898340. Its totient is φ = 5265552.

The previous prime is 6581929. The next prime is 6581959. The reversal of 6581945 is 5491856.

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 1510441 + 5071504 = 1229^2 + 2252^2 .

It is a cyclic number.

It is not a de Polignac number, because 6581945 - 2⁴ = 6581929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6581899 and 6581908.

It is an unprimeable number.

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, 658190 + ... + 658199.

It is an arithmetic number, because the mean of its divisors is an integer number (1974585).

Almost surely, 2^6581945 is an apocalyptic number.

It is an amenable number.

6581945 is a deficient number, since it is larger than the sum of its proper divisors (1316395).

6581945 is a wasteful number, since it uses less digits than its factorization.

6581945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1316394.

The product of its digits is 43200, while the sum is 38.

The square root of 6581945 is about 2565.5301596356. The cubic root of 6581945 is about 187.4065430550.

The spelling of 6581945 in words is "six million, five hundred eighty-one thousand, nine hundred forty-five".