6445581 has 4 divisors (see below), whose sum is σ = 8594112. Its totient is φ = 4297052.

The previous prime is 6445577. The next prime is 6445597. The reversal of 6445581 is 1855446.

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 6445581 - 2² = 6445577 is a prime.

It is a super-2 number, since 2×6445581² = 83091028855122, which contains 22 as substring.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6445501) 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, 1074261 + ... + 1074266.

It is an arithmetic number, because the mean of its divisors is an integer number (2148528).

Almost surely, 2^6445581 is an apocalyptic number.

It is an amenable number.

6445581 is a deficient number, since it is larger than the sum of its proper divisors (2148531).

6445581 is a wasteful number, since it uses less digits than its factorization.

6445581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2148530.

The product of its digits is 19200, while the sum is 33.

The square root of 6445581 is about 2538.8148810026. The cubic root of 6445581 is about 186.1032782889.

The spelling of 6445581 in words is "six million, four hundred forty-five thousand, five hundred eighty-one".